Anyone tried the Catalina AL20's

There are times when larger ONBOARD cylinders are warranted.. WHen I am doing some really big dives I use 7.5l lp steels that I'll bump up to 200bar or so.. A small 2l or 3l cylinder does not have enough gas to cover the loop if flushes are needed and the wing.. (in a DS I also use independent inflation)

a 150m dive can easily take up more than 1/3 the cylinder just making up the initial loop volume.. add this your wing and you may not have much to spare...

With the larger onboard cylinders the sling tanks are really for emergency use, not required gas for the dive...