Hi, there is a knockout on the back of the Plugmold. You will likely need end feed fittings to connect as well (option below - paintable with spraypaint). If you have any additional questions, please reach out to us at (800) 621-0049 and we would be happy to help! https://www.homedepot.com/p/Legrand-Plugmold-3-in-End-Feed-Fitting-Ivory-V2010A2/202520808
This power strip itself is rated for 15 amps, but you can use it on either a 15 amp or 20 amp circuit.
This outlet has 9 outlets.