Powerful blower that can be installed on many smokers using included adapter plates. Built-in sliding damper to fine tune airflow. Small/Medium Adapter Plate: 2.75 x 1.97″ (70 x 50mm) Large/XL Adapter Plate: 3.43 x 3.03″ (87 x 77mm) Specifications: Variable Speed, powered by FireBoard’s internal battery ** Power source: 12 VDC, 0.68A, 8W (not included) Cable length: 4.5 ft (1.4 m). Power connector: 2.5 mm barrel plug Blower maximum flow rating: 20 CFM Blower opening: 1.2 x 1.6″ (30 x 40 mm). Flange outer dimension: 1.95 x 2.45″ (49 x 62 mm). Flange mounting hole distance: 1.32 x 2.05″ 34 x 52 mm, hole size, 3 mm in diameter. Note: Blower does NOT include Drive Fan Control Cable, which is needed to use a fan with the FireBoard 2 or FBX11. FireBoard 2 Drive/Pro models will power fan directly, no Drive Fan Control Cable necessary. ** For maximum fan speed, external power is required.