The Expansion Clamp with 67 mm adapter arm is the ideal addition to the SeaTouch 4 Max underwater housing, specially developed for underwater video shoots. With three M6 fasteners on the top and three 1/4-inch fasteners on the bottom, you can flexibly combine the smartphone housing with a wide range of accessories - such as video lights, grab handles or trays. Made from CNC-milled aerospace aluminum, this clamp offers the highest quality and security for your smartphone.