BAR FLY 4 MINI HALTERUNG PLUS ZWEI BELIEBIGE COMPUTER-ADAPTER-EINSÄTZE (SIE WÄHLEN)
GoPro base attaches with M4x1x18mm screws and nuts, included. Once adjusted it is locked in place with a hefty M5 nut and bolt. You will have to use force to get your two-fin accessory in and out. Water may help insertion.