Olympus O-Ring (A) (Rear) for PT-023...

Replacement rear O-ring for the PT-023 Underwater Housing. Creates watertight seal. Olympus... Buy it:
$9.95 at Adorama
Olympus O-Ring for PT-021 Underwater Housing

Replacement O-ring for the PT-021 Underwater Housing. Creates watertight seal. Olympus... Buy it:
$9.95 at Adorama
Olympus O-Ring (C) (Front) for PT-023...

Replacement rear O-ring for the PT-023 Underwater Housing. Creates watertight seal. Olympus... Buy it:
$9.95 at Adorama