gas regulator window - When I painted the plastic cover ( with the prescribed Krylon Fusion-for-plastics "Dover White" ) I added a 1/8" polycarbonate plastic window, so as to see the auto-changeover regulator red/green window, without taking the cover off the tanks. The cover is easily cut with a utility knife. I made the plastic about 1/2" oversize all around, then used 6-32 bolts/lock washers/nuts for installation.