Rec-mounts Bolt Hole Mount for Gopro&reg; Gopro3 (Rec-b28(m8) 9mm Hole 9mm hole for M8 Long bolts, spacer, pure parts are necessary for the base mount CNC Machined 6061 T6 Aluminum 11g M6/M8/M10 Yes setting test move yutube http://www.youtube.com/watch?v=s7cTZPOwjaQ&feature=share&list=UUmpnbvEzq-LmiRRDJUakT_Q facebook https://www.facebook.com/recmounts cycle catarog(PDF) http://www.an-y.com/img/rec-mount-catalog3.pdf