SeaTouch 6 Pro filter kit

Again, the whole housing is inside this box, not just glass: the 6 Pro plus the filters that make it a color-correct camera rather than a waterproof phone.

Three filters instead of two. The red one covers 0 to 25 m in blue water, the magenta one handles green fresh water, and the third is cut for snorkelling depth, where a filter meant for 20 m turns everything into tomato soup. Each is aimed at a depth band rather than sold as one filter that half works everywhere.

The part worth the money is the hood. Shoot up towards the surface with a red filter and direct sun hits the glass, and the whole frame goes red in a way no amount of editing fixes. The hood blocks it. It is the sort of accessory you only know you needed after a ruined dive.

Mounting is a 67 mm adapter on an expansion clamp with two 1/4 inch threads, M6 holes and a cold shoe, so lights and arms have somewhere to go.