The most durable Rock Tumbler of its class. The drums runs at 20 rpm. Capacity of the drum is 17lbs (doesn't include the weight of the drum). This unit is comparable to the Thumler's Tumbler with added features and benefits that are a Must for cleaning rocks. 3 year warranty on unit, and 1 year warranty on motor. Key Features - High strength powder coating including inside the drum - Thick rubber lined drum - Large 1/2"" solid shafts with thick rubber rollers - Heavy duty sealed ball bearings - Seam welded, durable base with dual motor support brackets - Easy on/off nylon locking drum lid knobs - Longer lasting drive belt All New Heavy Duty Tumbler. This tumbler is comparable to Thumler's Tumbler Model B High Speed. It is the best way to go for tumbling rocks