This Sea & Sea replacement o-ring set includes all the user replaceable o-rings for the Sea & Sea TTL III converters and converters for the for YS-250PRO. 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.