Fitment Package including 4 x knobs.Suitable for most outdoor umbrella, tower vertical propane heaters, mini heaters and outdoor pyramid terrace heaters, suitable for fireplaces, fire pits, gas grills. Durability The control knob for patio heater is made of a strong material that can withstand high temperatures and frequent use, is more durable than other products, is not easy to deformation and rust, and reduces the damage of the stove knob. Funcition Patio heater control knob protector protects knob from grease and wear,stable and safe performance with good sealing which has the advantages of corrosion resistance and wear resistance. Easy to Install Changing the control knob for patio heater can be done in a short time without additional tools. Pull the old knob directly out of the valve stem, and then press the replacement knob back to the valve stem in the direction of port D.