Roof mountedPowerful and easy-to-install, these units supplement or replace air conditioning by removing the blanket of hot, trapped air from attics - automaticallyPrecision balanced 14 in metal blade for maximum air flow - minimum sound level23 ga metal flashing allows for nailing and hot tar applicationMesh bird screenBuilt-in adjustable thermostat for automatic operation at your chosen temperature levelThermally protected, permanently lubricated motorMounts easily between rafters installation template includedFor controlling use (purchase separately) model 69V (ivory)/69W (white) single-function control, model 68V (ivory)/68W (white) two-function control, model 72V (ivory)/72W (white) 6 amp electronic variable speed controlPVC plastic dome provides ultraviolet protection and superior durability8 in dome height from roof14 in Dia propellerShaded pole motorMounts easily between rafters installation template14-3/8 in Dia width roof opening