Model US-900, 10000 VPM (*vibrations per minute - speed will vary with load) adjustable eccentrics with 3 force settings at 10000 VPM Setting 1, 600 lbs. of centrifugal force; Setting 2, 950 lbs.; and Setting 3, 1100 lbs., 3.5 amps; 115 volt will handle test pieces up to 125 lbs. Model US-1600, 9000 VPM*, 3 force settings, 1100, 1600, 1900 lbs., 4 amps 115 volt will handle test pieces up to 200 lbs.