Features This button is suitable for action control in AC 50Hz, voltage 380V and below, DC 220V and below electromagnetic starters, contactors, relays and other electrical circuits. High insulation voltage reaches AC 660V and the rated voltage is 440V. Long service life.The mechanical service life reaches 5000000 times and electronic service life reaches 500000 times. With 2 levels of selector,the switch can be used in more areas. The switch works stable and very practical in use. Features: This button is suitable for action control in AC 50Hz, voltage 380V and below, DC 220V and below electromagnetic starters, contactors, relays and other electrical circuits. High insulation voltage reaches AC 660V and the rated voltage is 440V. Long service life.The mechanical service life reaches 5000000 times and electronic service life reaches 500000 times. With 2 levels of selector,the switch can be used in more areas. The switch works stable and very practical in use. Specification: Rated Voltage:440V Ui:AC660V Working Current:10A Level Quantity:2 Automatic Reset Function:No Contact Type:1 NO 1 NC Hole Diameter:22mm/0.87in Key Quantity:2 Rated Heat Current:15A Contact Resistance:50ohm Insulation Resistance:50Mohm Mechanical Life:5000000 times Electronic Life:500000 times Size:75 x 40 x 30mm / 2.95 x 1.57 x 1.18in Package List: 10 x Selector Key Lock Switch Package List 1 x Protection Board