I have a pair of LP steel 13 cu ft steel cylinders for sale. I bought these last year to use for some design work and never had the need to put them in the water. They are fitted with Dive Rite modular valves set up for an Optima (no remora) with the O2 cyl having a green knob, they are labeled oxygen and custom mix . They have 10/05 hydros and a new visual. $390 includes UPS shipping in the 48 states. If you wish to pick them up I will have them full for you (100% O2 and air) . Payment via Paypal. Call during the business day eastern time 518-843-6756 or email me mike@horseworks.com .