Review on 🎮 eXtremeRate Scarlet Red Soft Touch Custom Bottom Shell Back Panels for Xbox One S & One X Controller - Model 1708, Replacement Back Shell Side Rails w/Battery Cover by Gabriel Rosenberg

Very easy to assemble and looks very high quality, you will need the plus and minus terminals from your controller, the shell doesn't come with it but if you change the shell to your controller instead it will creating from scratch you still have a positive and negative band, but that's ideal, apart from being highly recommended