These cylinders are set up as rebreather cylinders, but call them whatever you want. Born on Date 04/07 and 05/06, hydro dates 03/12 and 01/12 respectively. I don't use these, and I'm tired of tripping over them. Buy one or both, and I can get a standard valve if you don't need the opposite side handle. I'd trade for Aluminum 19s in similar condition. $100ea + actual shipping and PayPal fees from 54603.