I have a MVE SC 20/20 semen tank for sale. The tank is charged regularly and there are not any problems with it holding it's charge. The tank has 6 canisters in it. My only reason for selling this tank is that I have reduced the size of my cow herd and breed all at one time so there is no need for me to have a semen tank year round. I am asking $275 for this tank and I don't think shipping will be a problem.