Choosing the right port system for your underwater housing is essential for achieving sharp, distortion-free images underwater. Whether you shoot wide-angle or macro, your port setup directly affects image quality, field of view, and usability.
Subal Extension Ring, 20 mm type 3€215.00 €177.69Special order product, non-cancelable, non-returnable !Subal EXR-20 / 3 extension - 20mm extensionring from Subal for type 3 portsystem Learn More
Subal Extension Ring, 20 mm type 4€215.00 €177.69Special order product, non-cancelable, non-returnable !Subal EXR-20 / 4 extension - 20mm extensionring from Subal for type 4 portsystem Learn More
Nauticam extension ring 10 with screws [21110]€214.00 €176.86In stockNauticam extension ring 10 with screws [21110]
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Subal EXR-13/ 3 extension€215.00 €177.69Special order product, non-cancelable, non-returnable !Subal EXR-13 / 3 extension - 13mm extensionring from Subal for type 3 portsystem Learn More
Subal EXR-13/ 4 extension€215.00 €177.69Special order product, non-cancelable, non-returnable !Subal EXR-13 / 4 extension - 13mm extensionring from Subal for type 4 portsystem Learn More
Subal Extension Ring, 28 mm type 4€235.00 €194.21Special order product, non-cancelable, non-returnable !Subal Extension Ring, 24 mm type 4 Learn More
ZEN ER.EP.25 extension Ring for Olympus PEN Housings€285.00 €235.54Backorder. Ready for shipment in 2 to 4 weeksZen Underwater 25mm extension ring for Olympus PT-EP housings and ports Learn More
Sea&Sea extension ring 20L (with lock for NX mount) [30123]€339.00 €280.17Backorder. Ready for shipment in 2-5 working daysSea&Sea extension ring 20L (with lock for NX mount) [30123]
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Subal EXR-33/4 Extension Ring 33 mm€235.00 €194.21Special order product, non-cancelable, non-returnable !To customize the ports to different lens lengths.
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Frequently asked questions about extension rings
What is an extension ring for an underwater housing?
An extension ring is used to position your lens correctly inside the port. It sits between the underwater housing and the port.
Do I always need an extension ring for an underwater housing?
No, not always. Whether you need an extension ring depends on your lens and port combination. This can be checked in the port charts.
How do I know which extension ring I need for my underwater housing?
You can use port charts to find the correct extension ring for your specific lens and underwater housing.
Are extension rings brand specific?
Yes, extension rings are designed for specific brands and port systems. Always make sure the extension ring matches your housing and port system.
Can I use the wrong extension ring on my underwater housing?
Using the wrong extension ring can lead to poor image quality, such as softness or distortion. Always follow the recommended setup.




