For most grill, heater, and RV propane tanks. Fits most 5 lb, 10 lb, 11 lb, 20 lb, 30 lb, and 40 lb. tanks. For a standard OPD/QCC1 valve with a 1.32" diameter Acme thread on the outside of the valve. The hole in the strap slips over the valve handle to prevent losing the cap. No tools needed to install. Prevents ice, dirt, and other crap from getting into your valve and clogging up up your system. For most grill, heater, and RV propane tanks. Fits most 5 lb, 10 lb, 11 lb, 20 lb, 30 lb, and 40 lb. tanks. For a standard OPD/QCC1 valve with a 1.32" diameter Acme thread on the outside of the valve. The hole in the strap slips over the valve handle to prevent losing the cap. No tools needed to install. Prevents ice, dirt, and other crap from getting into your valve and clogging up up your system. Dimensions (inches): 5.51 long x 1.49 wide x 0.78 thick (140mm x 38mm x 20mm)

The caps do NOT fit these: Most 50 lb and larger tanks. Small tanks without a hand valve. The fuel tank on a propane powered vehicle such as a forklift. Old style POL valves without threads on the outside of the valve.