Rola-Chem's Pro Series peristaltic chemical feed pumps deliver professional quality as well as features that make operation and maintenance simple. The quality is easily seen in the Pro Series' durable plastic construction that is resistant to swimming pool, spa, and hot tub chemicals. They are enclosed in vented, unbreakable stainless-steel cases and feature built-in, solid-state timers. Rola-Chem pumps are designed with 3-way bypass switches. They can be run on the timer position for interrupting action or can be run continuously when in the on position. The heavy-duty air-cooled motor has a thermal overload protection system and a maximum pressure of 30 pounds per square inch. Pump heads are molded of Lexan high-impact polycarbonate resin for durability.