The CEJN coupling system manufactured by CEJN AB of Sweden is notable for its reliability and ease of use. Today, the CEJN proprietary post is typically encountered on the inflation valves of drysuits used in commercial diving while most drysuits in recreational diving use the International (aka DIN, aka SeaTec) post. With the CEJN coupling system, having a chamfered edge means it does not have to be perfectly aligned to establish the connection and the collar only has to be pulled back when disconnecting the hose. Both Apeks and SI-TECH offer the genuine CEJN original 5mm high-flow post as an option on their inflation valves and are typically supplied by the drysuit manufacturers together with a low-pressure hose terminated in a matching genuine CEJN coupling. For maximum compatibility we recommend using a genuine CEJN drysuit inflation hose. Just to be clear, the proprietary CEJN coupling is NOT compatible with the standard International post found on most recreational diving drysuit inflators.

Various copies of the proprietary CEJN original 5mm high-flow couplings were used on some BC integrated second stages which are no longer manufactured such as the Aeris Air Link, Apeks Octo Plus, Beauchat Venturi, Oceanic Air Link, Oceanic Air XS, SeaQuest/Aqualung Air Source (but not the current Aqualung Air Source 3 model), US Divers Air Mic, and Zeagle Octo Plus. Collectively the quick-disconnect fitting on these devices is often generically referred to as the SeaQuest style connector (or sometimes Aqualung who later absorbed the SeaQuest brand), although there are slight variations among the devices. If you can't find the original equipment manufactuer hose then we do stock a high-flow quick connect SeaQuest adapter for a standard LP regulator hose, however in our experience the adapter may not be reliably compatible with every one of the posts on these various older devices.