They are supposed to be available from TUSA and SI Tech here in the USA. I know there is some compatibility issues with latex and silicone, so I am not sure if they will work for retrofit or new installation only or the difficulty of installing these. They look to be a HUGE improvement over latex seals which rip and tear very easily and degrade over a rather short time. I have latex wrist seals on my dry suit and they are starting to degrade. I am sure they are not going to make it too much longer, so I may try the silicone if replacements are available for my rig. I use a neoprene neck seal, and have no complaints about it and don't think I would want to change over to silicone on that one. The neoprene is way more comfortable for me then the latex and is very durable. Another benefit is that the neoprene is MUCH warmer then latex. I have also never had issues with any of my seals leaking....other parts of the dry suit, not so much.