The Sea & Sea Extension Ring 20L with Port Lock Feature provides manual focus for compatible zoom lenses. Extension ring is equipped with port lock features. Compatible Housings: MDX series housings and Compatible Lenses. The extension ring is equipped with a port lock. The ring is made of Corrosion-resistant aluminum alloy and provides distance Between the mount and the front end: 20mm / 0.8 inches (with port lock).Features: Equipped with port lockProvides manual focus for compatible zoom lenses

• Limited 1-Year Warranty

Limited 1-Year WarrantySea & Sea