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Model # GMS120

Internet # 202850662

Store SKU # 235338

Digital Wall Scanner

This item has been discontinued.
The Home Depot no longer carries this specific product.

$79.00 /each
  • Lightweight design
  • Durable and dependable
  • Suitable for a wide range of projects




Model # GMS120

Internet # 202850662

Store SKU # 235338

The New Bosch GMS120 Wall Scanner features Multi-Mode Detection-For wood studs, metal objects (rebar, studs and steel/copper pipes) and live wiring. Illuminated Graphical LCD Display-Indicates mode, detection strength and more. Deep Metal Detection Capability-Detects steel up to 4-3/4 in. (120 mm) deep in cured concrete. Automatic Center Finder-For locating center of detected wood or metal object. 3 Selection Modes (Wood, Metal, AC Wiring) with automatic calibration for easy and precise detection. Audible Detection Signal-With On/Off button. Ergonomic Soft-Grip-For secure grip and comfort. Illuminated ring indicates detection status.

  • Max detection depth copper wiring: up to 2 in.
  • Max detection depth ferrous metals (steel): up to 4-3/4 in.
  • Max detection depth nonferrous metals (copper): up to 3-1/8 in./80 mm
  • Max detection depth wood substructures (studs): up to 1-1/2 in.
  • Operating temperature: 14°F/-10°C-122°F/50°C
  • Home Depot Protection Plan:

    Home Depot Protection Plan
  • Great solution for all your detection needs


Info & Guides

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Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Audio alert 
Batteries Included 
Battery Type Required 
Detects metal 
Detects voltage 
Digital Display 
Hand Tool Type 
Stud Sensor 
Laser level included 
Maximum wall thickness (in.) 
Number of Batteries Required 
Tools Product Type 
Hand Tool 
Warranty / Certifications
Manufacturer Warranty 
2 Year 


Rated 3.6 out of 5 by 53 reviewers.
Rated 4.0 out of 5.0 by Quality Wall Scanner I was frustrated buying cheap, throw-away stud finders that never seem to work when you need one, so I stepped up to the Bosch GMS120 Professional Wall Scanner. It comes with a nice flexible storage case with hand lanyard and belt loop. Using this wall scanner is not intuitive and requires reading the instructions thoroughly. There are multi-colored flashing lights, changing bar graphs, symbols and sounds that requires prior working knowledge to use properly. The instruction pamphlet would benefit from better graphics and illustrations. The scanner has three modes; wood, metal or live electrical. In the wood mode it actually scans for all three, and will display the various signals and graphs on the display. It also identifies the center point of wood studs or metal objects. Selecting metal mode excludes wood and scans for only ferrous/non ferrous metals and “live” electrical wires. It is important to note that the scanner detects wires where current is flowing. The warning light may not flash for wires that have no current draw. The Bosch GMS120 performed very well in all three modes during my testing and use. As recommended in the instructions, I used a thin piece of cardboard over the uneven ceiling texture, and it detected the joists perfectly. Now I don’t have to drill and patch holes in the ceiling when looking for the joists. The scanner could be more user friendly with better graphics in the display, but it’s still a giant leap above the cheap stud finders. April 25, 2013
Rated 2.0 out of 5.0 by High hope deflated. Had high hopes for this detector as Bosch makes great products. I liked the size and layout of the buttons and the backlight is great for low light areas. Thats about as far as the pro's went. The detector reads a green light as a you scan and flashes red when an object nears - confuses me, imo. it should be the other way around. When you approach an object the display "bar segments" increase until the center is found. Sounds great but I had so many false readings i didn't know what was behind the simplle 1/2" sheet rocked wall. I compared the same wall w/ a B&D dtector and had much better results. Bottom line save your $. September 10, 2015
Rated 2.0 out of 5.0 by Disappointing This stud finder really sounds like it does it all: find studs, live wires, and metal in the wall. However, I was very disappointed that it didn't perform better for the price. My $15 stud finder outperformed it on several of the walls that I tested it out on, which is inexcusable in my book. Initial impressions: - The stud finder is a little bit larger than most I've used in the past. - Bosch packed a lot of features into this, including a 3-color led indicator, a signal strength display, a backlit display, the option to turn sound indications on/off, and the option to turn the backlight on/off. - The through-hole for marking stud locations is a pretty cool feature too. Wood stud detection: - The main application I planned on using this for was locating studs. I started over an electrical outlet, since I knew there should be a stud on one side of it. I used both stud finders (my old one and this one) simultaneously, and my old one lit up reliably every 16", turning on and off for each side of the stud. The Bosch gave me intermittent indications, some of which were right in the middle of the 16" spans. The centering feature is OK, but requires that you backtrack once you reach the far side of the stud. Even then, it usually gives about a 3/4" range that it calls the "center." Metal detection: - The best-performing feature is the metal detecting capability. This is the only reason I'm giving it more than one star. I do a bit of woodworking, and missing a nail before I send a board through my planer can cost me $50-60 on a set of knives. So if I find two nails, the scanner has paid for itself. I tried it out by holding a screw on the far side of an 8/4 walnut board, and the scanner gave a strong indication when I passed over the screw's location. It couldn't find a staple through the board though, but it can detect a sewing needle from about 1/4" to 1/2" from the scanner, without anything in between. - If you want a more reliable stud finding method, I'd use the wood detection capability in conjunction with the metal detection feature. Find the general location of the stud with the wood detection, then use the metal detector to scan up and down to find the screws. Live wire detection: - This thing is garbage when it comes to finding live wires in your walls. I can scan all around electrical outlets and light switches without so much as a peep from it. My old $15 stud finder lights up like crazy when I scan the same areas. I even scanned the extension cord powering an overhead light in my garage, and the Bosch scanner couldn't pick it up even when I touched them together! I had to rub the wire all over the scanner until it lit up. I would definitely NOT trust this thing to find a live wire before I drilled into the wall. Conclusions: - Unless you are buying this in part for the metal detection capabilities, go with a different scanner. Even then, you may still be able to find a separate stud finder and metal detector for about the same total price. May 19, 2013
Rated 1.0 out of 5.0 by POOR SCANNER HIGH PRICE As much as i like Bosch products, their wall scanners are not accurate at all. My new $20 scanner scans better than this one. Thanx to Bosch scanner i put a nail into the BX (electrical wire in the wall) under the electrical box that was covered by a painting :-( The Bosch scanner didn't show any electrical in this area and it was a regular sheetrock wall... Ended up returning the unit and paying a huge repair bill... Stay Away from this scanner.... November 30, 2013
Rated 5.0 out of 5.0 by Great scanner This scanner is so easy to read . It can find studs in walls that other scanners cant find. It is lightweight and so easy to get into places that you cant do others March 3, 2015
Rated 1.0 out of 5.0 by I got a bad unit... My unit wouldn't pick up anything correctly, wood, metal or electrical. It gave out false readings constantly and led to much aggravation. After some online research I discovered that Bosch sent some faulty units to the states. I called Bosch and they confirmed the bad units being shipped over to the U.S. I attempted to return it to the Home Depot store where I bought it only I had lost the receipt and the store had pulled the stud finder from their shelves so they refused to take it back. Now I am stuck with an $80 paper weight. I will purchase a new one because I trust Bosch products but I will not buy it from Home Depot. August 27, 2014
Rated 5.0 out of 5.0 by A professional grade tool. If you are after something to locate studs for hanging a picture or mounting a TV, then this detector is overkill. But if you are a serious modeler, or need a full featured detector, this is the tool for you. I should warn you that there is leaning curve if you want to make full use of this detector. It presents a lot more information then a standard stud detector. There is the audio output like a basic stud detector. I find it annoying, but you may find it useful. It would be nice if it had a volume control, but at least you can turn it off. And the detector remembers for the next time you use it. It has a detector. It has a centering hole, with a ring around it that changes color to give a quick visual indication. Then there are two bar graphs that show "signal" strength, and centering. The centering graph is easy to use, but it needs to calibrate itself, so it is not going to show you the center of the stud until you hit the far edge. This is because it does not know how wide the stud is before then. But once it knows, you can back up the scanner and get a good center reading. Once you get used to it, you will love it because it gives you the true center. It works the same for other detection modes. The strength meter will give you an indication of how deep something is in the wall. Once you get a feel for it, it will let you estimate how deep or how big a metal object is. It is handy for telling the difference between a nail and a buried cable or pipe. The icons will tell you when it is detecting something for a different mode then you are using. If you pay attention, it can save you from cutting a wire. The mode button you select lights up to remind you what mode you are in, and there is a light you can turn on to illuminate the LCD display. Someone was thinking when they designed the scanner. I was able to try it on both plastered and drywalled walls. I was luck to have 2 walls where I know the location of the studs, so I could test how accurate the detector is. For the drywalled walls, it was very accurate. For plaster walls, the results were not as good. From past experience, I was surprised that it could detect the studs at all. It did much better when set to detect the nails fastening the lath to the studs. How well the live wire detector works depends on the wiring. If it detects the wire, it will give you a nice map of how it runs. But if you have BX, or knob and tube wiring, it may not detect the wiring. The metal sheathing on the BX effectively blocks the signal from the live wires. With knob and tube wiring, it will usually detect the wires to a switch if the switch is off, and their is a light in the circuit. If the switch is on, it may miss the wires. All non-contact detectors run into the same problem. Luckily it is rare to run into knob and tube wiring. I just happen to have a house that is over 100 years old, and has several different types of wiring. So it presents interesting challenges that you don't normally run into! May 3, 2013
Rated 5.0 out of 5.0 by Great features. The features are great...takes the guesswork out of locating the studs, etc. January 13, 2015
  • 2015-10-07T10:25:01.959-05:00
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