Marshall Excelsior Propane Adapter Tee Model ME425P. The ME425P Excess Flow Elbow is designed to be used with RV propane cylinders with the new Type I, QCC ACME connection. The elbow has a 1in 20 male high pressure LP gas connection port for powering portable camping appliances such as camp stoves, lanterns, table top grills, and other small LP appliances. The ME425P elbow connects to MEC camping appliance hoses MER421-60 and MER421-144 (Coast#57533, 57532 sold separately). QCC Type I x FPOL x Male 1in 20 x 1/4in IF, packaged.