Posted May 12, 20241 yr Hey all I have two discontinued S&S ports for which I'm trying to find new O-rings: Extension Ring 20L (SS30123) and DX Macro Port 52 (SS30111). I've searched a few websites but haven't found any. Does anyone have an idea where I can find those?  Thanks 🙂
May 12, 20241 yr Industrial parts suppliers (in Australia anyway) stock a huge range of O rings. Suggest take your old ones in to a bricks and mortar store and have them measured. Industrial replacements may not be made of the same material though. Be sure to test the housing (vacuum or in-water) with the new O rings before risking a camera.
May 13, 20241 yr If the OP is in the US, McMaster-carr has a great selection of o-rings. You just need to determine the correct size.  https://www.mcmaster.com/products/o-rings/   Edited May 13, 20241 yr by SwiftFF5
May 14, 20241 yr if you just want to buy new o-rings rather than go to a store or try to measure yours, I think you will find that all S&S ports that fit your S&S housing will take the same o-ring. there is no reason they would change between different ports. as they all need to fit into and seal against any housing that takes that port type.
May 14, 20241 yr You can ask Bluewater, Backscatter in San Francisco, or B&H Photovideo if they have the O ring: https://www.bhphotovideo.com/c/product/1188855-REG/sea_sea_ss_30123_extension_ring_20l_with.html  or you can measure the O ring and buy it from The O Ring Store, Backscatter, Optical Ocean Sales, etc. The two measurements of an O ring are its inner diameter and its cross section, in millimeters.   The O Ring Store link is: https://www.theoringstore.com/store/index.php?main_page=index&cPath=345&gclid=CjwKCAjwl4yyBhAgEiwADSEjeG00b9LEwYK8A5rWlw7mqlqdNzsYNp_XMbXoCM0mMMcwrCiMhXtmcxoCTCQQAvD_BwE Edited May 14, 20241 yr by Kraken de Mabini
May 14, 20241 yr If you know the dimensions, you can also try a simple eBay search. There are different materials (silicon, NBU etc.) - a lot of technical O-rings sold there will be NBU but the housing & port O-Rings are likely silicon. I‘d stick with that if possible. Even if you do find the exact same size, a third party O-Ring may not be quite as supple as the original. This probably does not matter in absolute terms, but a less supple seal means perhaps that sand, hairs or jolts will more easily lead to water seeping in. Less forgiving so to speak. If you can still find an original it‘s worth the extra money, but if not the third party ones are at least really affordable.