Designed for use with bulk tank hoses, the Mr. Heater Universal Fuel Filter keeps the fuel line clean. Due to contaminants found in propane tanks and propane hose assemblies, it is required for use with all Portable Buddy and Big Buddy Heaters when attaching to a 20 lb. tank. Made of galvanized aluminum, it has 1" - 20 throwaway cylinder threads. Most commonly used with Mr. Heater hose assemblies F273701 (5ft.) and F273702 (12ft.). It measures 3" L x 2" W and is designed to connect to the built in regulator on our Buddy appliances and then to the hose assemblies. It does not connect directly to a propane tank. Made of galvanized aluminum Connects to Buddy appliance regulators & hoses Does not connect directly to a propane tank