On the outside of the water rack we had S.N.A.F. install two heavy-duty Straight Jacket Powertank brackets. These will serve as a secure mounting location for CO2 and nitrogen cylinders. We like these brackets because they were designed to survive the tortures of Baja. Constructed from 13-gauge steel, these brackets lock down any standard 20-pound-or-smaller bottle with two wraparound stainless steel straps. We think these are the perfect balance between high strength and light weight (3.8 pounds each).