TJERNLUND AUTO-DRAFT® Inducers assure positive draft when restricted boilers and furnaces, poor chimneys or slight negative pressures in buildings prevent proper exhaust of combustion gas. The venturi action of Tjernlund Auto-Draft Inducers starts air moving smoothly. These units are quick and easy to install and completely automatic in operation. Tjernlund's unique design and durable construction makes them trouble-free and reduces maintenance to a minimum. The Vari-Draft Control permits adjustments to the individual job requirement. Tjernlund Draft Inducer, In-Line, 115 VAC, 0.43 A, 35 W, 3 to 6 in, 2-5/8 x 7-1/8 in Cut Out, Aluminized Steel Housing, 8-1/2 in W x 5-7/8 in D x 7-1/2 in H, Domestic