4 in. Plastic Pop-up Drainage Emitter

No. It is manufactured in USA.

Thanks for your question. Your concern is valid. Although these popups are rather sturdy, indiscriminate overruns by commercial mowers might damage the popup assembly in two ways. First, a high lift mower may pull the popup up and sever it. Second, very heavy weight wheels of commercial mowers could crack the horizontal pipe (if using solid sewer pipe - use of the corrugated flex pipe takes care of that problem). One idea, depending on the landscape design, is to have the popup placed just off the turf line on the edge of a flowerbed/planting area.

Thanks for your question. If the cover fails to seat properly after a rain event, I'd first remove the entire green top unit. Examine the center support area to see if debris has lodged there. Examine the inside of the pipe in the ground to see if it is draining properly. Installation of such a system recommends a 1/4" hole through the bottom of the in-ground pipe near the elbow which points upward toward the popup (I use and recommend a 1/2" hole and a bed of quarter stone beneath for better pipe drainage). Reach in and remove any debris. Clear the drain hole with a wire coat hanger. If no drain hole already exists, you "may" be able to drill one using an extra long specialty drill by angling down the open pipe hole. If not, then it's a digging job to expose the pipe and drill the hole. If so, then I do recommend additional digging beneath that section of pipe and backfill that area with quarter stone (available in the cement area of Home Depot not the lawn and garden section).

It happens- drive a screw or two from the side into the pipe- it’s just the rush of water- that will hold it in place

The elbow will connect to 4" Sewer and drain pipe.

Thanks for your question. A couple options come to mind. First, yes you can remove the green top, reach in with your hand and remove the debris. You may find it convenient to reduce the debris entering the system. Debris grates can be installed (boxes with angled grids) that encourage large debris from the downspout to slide down and off the grate while the water continues down into the pipe. Also, a catch basin with filter can be installed where the downspout currently enters the pipe. The catch basin can be easily cleaned by hand.

yes

Very similar. It functions the same way and used in the same application. The 421 is slightly different in design.

The bottom of the elbow to the edge of the outlet is 7.5 inches. If you need deeper, you can consider installing a vertical PVC riser as the green emitter top disconnects from the PVC elbow. Keep in mind that this is not schedule 40 PVC but is sized for sewer drain pipe. You might find it difficult to find the solid white 4" drain pipe in this store, however. Note that the "bell end" of the sewer pipe would mate with the green emitter top, and the non-bell end would fit inside the elbow. Another alternative is to use the black corrugated "drain tile" tubing. NDS sells the adapter at Home Depot that connects such piping to the PVC elbow. If the corrugated piping/adapters are used, I recommend sealing the connections with RTV silicone as well as securing with stainless steel screws. There's also a competing brand popup emitter with corrugated drain tile tubing already attached which is sold by Home Depot, but I'd stick with the NDS brand products if possible due to their reputation.

That isn't what is needed in the case you mentioned, you would need to use a spreader to widen the discharge and you should dig out an area about 1 foot larger than the spread then fill it about 1/3 of the depth with gravel then top that off with larger stone. the size of gravel and stone may be determined by asking your Home Depot for advice in your area.