Philadelphia Mixers Stainless Steel Pneumatic Mixer. Model: PGA-6-2. This portable, variable speed, clamp on mixer is powered by a pneumatic motor and gear drive which provides maximum torque output, reduces heat build-up and allows for spark free operation. Impeller diameter: 12-1/2 in. Pneumatic motor: 2.0 hp, 1750 rpm. Gear drive ratio: 5:1. Final rpm: 350. Air inlet: (1) 3/8 in. push on air hose fittings. Shaft dimensions: 3 ft. 7-5/8 in. L x 1-1/4 in. diameter. Overall dimensions: 1 ft. L x 1 ft. 1/2 in. W x 4 ft. 10 in. H. (ACN32)