Oscillation: UltraSonic LLC’s 3200 and 2400FA machines offer greater cleaning power through oscillation (i.e., up and down, and in and out), which attacks the part or parts from different spots and angles throughout the cleaning cycle as the part or parts pass through different parts of the tank. Many manufacturers don’t offer oscillation; in their machines, parts are simply set in a basket and stay motionless once the cleaning cycle is started. When that occurs, dirt or oil that floats on top of the water comes to rest right back on the parts as they were before the cleansing process began.