This Olympus POL-042 O-Ring is for the PT-043 and PT-042 underwater housings. The PT-043 is for the Olympus Stylus 1030 SW Camera. The PT-042 is for the Stylus 1010 and 1020 cameras. 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.