Specification: Can be used under bad condition; As the switch is sealed isolating internal mercury from external; Therefore it can be used in oil steam dust and corrosive gas Features: Needs small external force during on / off; Mercury is the only metal that is liquid at room temperature; It surface tension and density is larger a little force can make the switch tilt and lead to mercury moving to make switch on / off; The conductivity of the mercury is good contact resistance between the electrodes is less than 100m ohm; Allowable current of switch depends on the electrode material tungsten electrode for 10A max. while wire is 1A max.; Can be worked in stable for long time; No noise small and variable; Switch can be on / off if the acceleration reaches more than the set value thus it can be used as a vibration sensor; Simple structure and low cost Application: DIY switch