The RV Thermo Pigtail Type I ACME provides a safe, user-friendly connection from your Marshall Excelsior MEGR-253/253H regulator to a standard LP gas cylinder without the use of a wrench. The easy to tighten nylon nut swivels on a connector fitting that is heat sensitive. Inside the brass nipple is a flow-limiting device designed to sense excess gas flow. If excessive gas flow is detected, the RV Thermo Pigtail will shut down the flow to a maximum of 10 SCFH by-pass flow.Note: MEC Green type I nut for use on RV application only 200,000 BTU per hourBetween 240 DegF and 300 DegF the brass nipple displaces approximately 1/4 in. closing the cylinder valve module and stopping the flow of gas from the containerRed female QCC, type I x 1/4 in. MNPTFlexible thermoplastic UL and CGA approved hose15 in. hose length. These products contain a chemical known to the state of California to cause cancer and birth defects or reproductive harm – https://www.p65warnings.ca.gov/chemicals/lead-and-lead-compounds