The Spring 3K Light Meter is engineered to check the out-put of high-speed curing lights: a switch feature permits its use with conventional curing units as well. The unit is set at 0-3000mw for high-speed curing light testing and at 0-1000mw for conventional lights. Each 3K Light Meter has been calibrated against a standard for accuracy. For additional information, please contact us at 1-800-800-1680 or email: springhealth@email.com