Cast aluminum hand crank blower. 1:28 gear ratio. We chose this blower to pair with our forges because of the quality of the construction and design. It is imported from India where the basic design has been in continuous wide spread use since the time of the British Empire. The drive is a backdriven worm gear with a high quality steel worm and cast iron gear. The main shaft rests on bearings for smooth, long lasting operation. Two toggle lid oil ports make maintenance easy. Round is 7.5" diameter, weight 8 pounds. Comes with a one year guarantee.