Sony’s Back Button attachment will improve your game on the cheap, but it costs a few headaches.
PlayStation 4 DualShock finally has cost-friendly back buttons: Review
DualShock 4 Back Button Attachment Review, by Alex Rowe
DualShock 4 Back Button Attachment - PlayStation 4 : Video Games
DualShock 4 Back Button Attachment - PlayStation 4 : Video Games
DualShock 4 Back Button Peripheral Adds 2 New Buttons To PS4 Controller - IGN
PS4: DualShock 4 Back Button Attachment, Unboxing & Review
PS4's Back Button Attachment Is Impressive, Comfortable, and May Tease the PS5 - IGN
FINALLY!! PS4 Back Button Attachment Review
PS4 Back Button: Controller attachment release date guide - price, reviews, where to buy, Gaming, Entertainment
DualShock 4 Back Button Attachment review - Polygon