The ACC-MP101 Sony O-Ring is for the underwater housing
MMPK-THG. The housing MMPK-THG is for the Sony DSC-T700, and T77 digital
cameras. The o-ring resembling a thick rubber band is designed to
establish a watertight seal when going underwater.
to precision tolerances required to hold a pressure seal on your housing
and made of elastomeric material, it provides the means by which a
watertight seal is formed.