Use these steel Mob Discs to expand the mounting options of your MobNetic Pro 90 or Action Cam Mounts. Each Mob Disc is only 1.5 inches in diameter and can fit just about anywhere that is flat. The backside of each Mob Disc has 3M VHB that will adhere to almost any surface. Accessory pack comes with 2 Mob Discs, and 2 alcohol wipes. To apply: clean the surface with the included alcohol wipes, hold Mob Disc firmly on the surface and let the adhesive set in, wait about 4 hours before use.