Features: High insulation voltage reaches AC 660V and the rated voltage is 440V. With 2 positions of selector,the switch can be used in more areas. The switch works stable and very practical in use. Long service life.The mechanical service life is 5000000 times and electronic service life is 500000 times. 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. Specification: Model:BEM38-11Y/21 Rated Voltage:440V Ui:AC660V Indicator Light:Red/Green(optional) Working Current:10A Level Quantity:2 Function:Self-Locking knob Contact Type:1 on 1 off Hole Diameter:22mm/0.87in Rated Heat Current:15A Contact Material:Silver Contact Resistance:50ohm Insulation Resistance:50Mohm Mechanical Life:5000000 times Electronic Life:500000 times Size:90 x 32 x 30mm / 3.54 x 1.26 x 1.18in Package List: 10 x Selector Key Lock Switch