UNICO L-RT28 Rotator is a compact, durable, variable speed orbital mixer that will accommodate a wide variety of printed well slides, culture plates, flasks and small test tube racks, as well as RPR and VDRL slides or 96 well microtiter (immunoassay) plates. It features a 11"x11" mixing plate with a removable/replaceable rubber pad; variable speed of 25 to 250 rpm; a tachometer with an analog rpm indicator (adjustable); 3 position switch for Constant On/Off/Timed Mixing; indicator bell at end of timed mixing cycle; and small flask hold down spring.