It is made of high-density foam material, with low weight and small volume so as not to affect the camera grip. Its fit is stable and it does not slip, however it is somewhat difficult to put on the first few times until it "opens up" slightly and care is needed when removing it. The bright orange color helps it be spotted immediately in the water, offers real safety in water shots, does not weigh down the setup and does not affect anything. It has proper cutouts for immediate access to all the camera buttons and screens.
It slightly increases the camera's volume.