The photo lead has the same shape as the foam included in the U-A, U-AX, U-AXP and U-AZ. This foam piece can be replaced by the lead. The BF1 is coated with a soft latex to ensure, that it will help protect your equipment.

The weight is covered in a special latex to ensure that the can not leave any marks on or scratch your camera.

Please note, that the flexible housing behaves just like the organs of a diver with regards to water pressure. As stated by the law of physics of Boyle-Mariotte (pressure x volume = constant) the volume of air in the housing (just as that in the lungs, diving jacket and the air inclusions in the diving suit) decreases as it descends. In other words, a housing that is positively buoyant on the surface will be neutral at a certain depth and thereafter even show a tendency to sink. This point can be "adjusted" by adding weights to the housing, the amount of air included in the housing and some practice...

Please also read: "How much air should be in the closed housing?"