This Ikelite 5512.69 o-ring kit is for large Ikelite SLR housings. The kit consists of one body o-ring (0132.61) and one port o-ring (0105). The o-ring resembling a thick rubber band is designed to establish a watertight seal when going underwater.
Manufactured 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.