This is a 4 pack of XL bolts that slide into the T track on top of your Photon V2, V2+, or V2 Pro. They are most commonly used for integration with T tracks, BOT mounts, T5 hybrid kits, and other DIY add-ons. These bolts are twice the length of the ones included with your Photon. They have M6 (6mm) threads with a pitch of 1.0 and length of 15mm (about 1/2″). These bolts are custom made to be used with your Photon and are stainless steel.