One (1) used Tyler Rotap Sieve Shaker. Model RX-29. The RX-29 model is designed for testing with 8" diameter test sieves. Unit features 99 minute digital timer/clock, tolerance, 0.1 second.The Tyler Rotap uses a horizontal, circular motion and a vertical, tapping motion. This action allows material particles to stratify and seek critical openings in the test media. Testing application from 2" down through 635 mesh (20 micron).