The waterproof case weight ww dc1 is an additional sold separately accessory to the canon waterproof case that can be used to prevent the case from floating while taking pictures underwater four pieces of weight plastic pins and weight securing screws are included in the ww dc1 package in using this weight please put two suitable pins into the required number of weight fasten it to the waterproof case with the securing screw in the case that other accessories are attached to the waterpr