The expansion clamp and lens adapter are the key extension accessories of the SeaTouch 4 Max housing for underwater photography. Multiple ways of mounting are integrated in one single clamp, including different specification threads M6 and 1/4" to adapt various kinds of underwater photography accessories. The cold shoe connector is integrated to fit more gears. With an adjustable-length lens adapter, you can attach wet lenses, filters, a tray, and lights to the housing to fully equip it for different underwater scenarios.