PlayStation 4 prototype controller reportedly leaked in dev kit photo - Polygon
Ben Heckendorn on Twitter: "Prototype finally done. Single handed PS4 controller using the Hori PS4 mini controller. https://t.co/1nNsP4Jbz5" / Twitter
Here's What Different Prototype Controller Designs Look Like
Selling Like New Prototype PS4 Controller - Buy, Sell, and Trade - AtariAge Forums
These PlayStation 4 controller prototypes may have been forged in the depths of hell - MSPoweruser
Added two new Playstation prototype controllers to go along with my PS4 prototype. : r/gamecollecting
PS5 / DS5 Controller Rumors Surface Amid New Pictures from Tidux! | PSXHAX - PSXHACKS
Guerrilla Games Put a Stop to Touch Sensitive PS4 Controller Prototype | Push Square