Rotap Model RX30 Sieve Shaker with ability to accept up to 12 in dia Sieves, C/S frame mounted on S/S table, 1/4 HP drive motor, For material analysis 2in down through 20um (US # 635), Oscillations per minute: 278 +/- 10, Displacement 1.125in x 0.4375in, Taps per minute: 150 +/- 10, Controlled Amplitude for Consistent Results, Laboratory tabletop Design, small foot space, and quiet operation, Two settings for fine and coarse sieve analysis with three dimensional action