3 vent heating system. A complete heater system that includes one 40,000 BTU Heater 45° wrapper with wire harness, universal mounting brackets & screws, heavy duty wire ties, one High low switch with indicator assembly, stainless hose clamps, Two(2) 1st Generation Hot Tubes™ & One(1) Fixed Louver, 50\' of Heater Hose, One(1) Low Idle \"Y\", Brass Fittings, and installation manual.