1The electric shock part is made of silver alloy material, durable and long service life. 2This switch has three gear which is easy to control 3The contact form adopts 2 groups normally open, it has stable performance 4The size of opening hole is 22mm which is convenient to install 5This button is suitable for AC 50Hz, voltage 380V and below, DC 220V and below electromagnetic starters, contactors, relays and other electrical circuits play a controlling role Features: 1. The electric shockpart is made of silver alloymaterial, durable and long service life. 2. This switch has three gear which is easy to control 3.The contact form adopts 2 groups normally open, it has stable performance 4.The size of opening hole is 22mm which is convenient to install 5.This button is suitable for AC 50Hz, voltage 380V and below, DC 220V and below electromagnetic starters, contactors, relays and other electrical circuits play a controlling role Specification: Condition: 100% Brand New Model: BEM38-20Y/31 Rated Voltage: 440V Insulation Voltage (Ui): AC660V Working Current (IthIth): 10A Number of Gears: Three Gear Contact Form: 2 Groups Normally Open Opening Hole Size: 22mm Number of Keys: 2 Rated Heating Current: 15A Electric Shock Material: Silver Alloy Contact Resistance: 50 Insulation Resistance: 50M Mechanical Life: 5 Million Times Electrical Life: 500,000 Times Size: Approx. 75 * 40 * 30mm / 3 * 1.6 * 1.2inPackage List: 10 * Key Switchs