The Smart Check provides you with reliable back-flow prevention without the inline restriction of a conventional check valve. With the use of high powered magnets, the Smart Check valve remains in the closed position to 2 PSI, opening fully when 2 lbs. line pressure is exceeded. The Smart Check has a spring-loaded gate mechanism allowing the valve to be installed in any orientation. The valve is also available in a non-magnetic, 1/2 lbs. spring-loaded version.