mccabe links, resettable fire links, phl links, fire/smoke thermal electric releasing devices, ul 33, underwriter's laboratories, heat testing, safety devices, bi-metal link, save time and money, environmentally freindly,fire doors, smoke vents, dampers, hatches, range hoods, fire extinguishing systems, ce, phl links, llc, 3916 traxler court, bay city, mi 48706, phone: 989 671 9414, fax: 989-686-8152, e-mail: info@phlinc.com, spec sheets, redundancies to heat operation, never needs replacement to comply with ul, nfpa and local code periodic or continuous cycle safety system components testing, provide heat detection signaling and operations, manually click to reset it, nuisance tripping is reduced by the built-in delay.