Build Your Own PS4 Controller! Custom PS4 Controller - Aimcontrollers
Amazon.com: DualShock 4 Back Button Attachment - PlayStation 4 : Video Games
eXtremeRate Textured Black Dawn Remappable Remap Kit for PS4 Controller with Upgrade Board & Redesigned Back Shell & 4 Back Buttons - Compatible with JDM-040/050/055 - Controller NOT Included – eXtremeRate Retail
Strike Pack for PS4 Controller, Controller Back Button Attachment,Paddles for PS4 - Walmart.com
Trigger Back Button for PlayStation®4 – Nyko Technologies
Personalized Custom PS4 Controller Back Decal Sticker make it your own label | eBay