The ikelite o-rings they are usually made of very soft silicone material, and they need to be periodically washed under running water and then lightly lubricated exclusively with the grease supplied with the case, otherwise the O-ring will deform and stretch. it must be replaced at least once every 2 years for those who use the Flash occasionally, every year for those who use the Flash more than 40/50 dives per year during periods of non-use it is advisable to remove the o-ring from the Flash and place it in a closed plastic bag, if you leave the o-ring mounted it is advisable to keep the battery pack removed from the Flash , to avoid crushing the o-ring. a good fotosub always has a spare o-ring with him, it is impossible to find it on an island in the Maldives, but also in 90% of the.
eBay