The matained (locked-on) rotary cam switch stays in place when you release the switch. The momentary (spring-loaded) rotary cam switch is a spring-loaded feature means that it automatically moves back into place when you release the switch Made from high-density plastic. Maximum 20 amps. Recommended up to 1 HP motor. Maintained (lock-on) vs. Momentary (spring-loaded) The maintained (lock-on) drum switch stays in the position you place the handle until manually turned off. It does not have guide arrows on the front plate. The momentary drum switch handle springs back to the off position when it is released. It has guide arrows on the front plate. The momentary (spring-loaded) switch is the safer choice because it won’t operate unless someone is holding the handle.