Beware of being unable to get them filled away from where you bought them, I was interested in the concept
of light weight, non rusting tanks with a visual as to the level in the tank. I checked with one of the larger filling stations and was told that they are not accepted in New Zealand
, (Australia?) and he has had to deal with a lot of frustrated overseas yachties who didn't want to replace their tanks with steel
/ SS / or alluminium that have been through the bureaucratic hoops and have been certified.