The PTS540 JK035 SMTR LFS is a surface-mounted tactile switch made by C&K. It has a small profile, a 0.4 mm actuation height, and a light-force snap action. It is single-pole, single-throw switch with a momentary action, meaning it is normally open and closes when actuated. The switch was designed to offer enhanced haptics and audible feedback, with a tactile spring and audible click for a reliable user experience. It is available in LED or non-LED versions and is suitable for use in a range of applications including consumer, medical, and automotive electronics.