This Sea & Sea o-ring Set is for the Sea & Sea RDX port and port base. The o-ring goes in between the port and RDX housing. 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.
O-Ring care guide
Sea & Sea
O-Ring Set for RDX Port & Port Base