The Everbilt Satin Nickel Spring Door Stop is 3 inches long.
This Chrome Spring Door Stops are not currently available in a 5 pack.
No. They are "brass finish". Checked with magnet - spring steel underneath.
Yes, there are bigger packages the contain more than just one. I only needed a few so I purchased them individually
There are a few options in stock at store #622 - part numbers 13531, 14515, or 15727. Links provided below. https://www.homedepot.com/p/Everbilt-Oil-Rubbed-Bronze-Kick-Down-Door-Stop-13531/202950148 https://www.homedepot.com/p/Everbilt-Oil-Rubbed-Bronze-Step-Release-Kick-Down-Door-Stop-14515/206743153 https://www.homedepot.com/p/Everbilt-Oil-Rubbed-Bronze-Commercial-Grade-Kick-Down-Doorstop-15727/202034257
This is 4"
This stop measures 3" long.
The spring itself should unscrew from its base. Thus giving you access to the screw. You may want to watch the installation video on this web page.
Either is fine (unless you have a hollow core door then baseboard is your only option) but consider your location. If high traffic area mount on door otherwise baseboard mounted will be kicked, stepped on, tripped over and ruined. If door swings against a wall where furniture may someday be placed mount on door otherwise you'll need to remove the stop to put your furniture against the wall. I prefer door mount, makes cleaning easier for the homeowner and less likely to get ruined by traffic.