momentary type: push on, release off （no locking） latching type: push on, push again off (locking)   Part number:15A big current Metal push button switch, momentary/latching (PM191-Q-11/S, UL ) Install diameter:19mm Switch rating: 15A/250VAC (Resistive load) Shape: Flat head Function:Momentary (Push on,release off)  (1NO1NC) or Latching (Push on,push again off)  (1NO1NC) Terminal: 3Pin terminal ( 2.8*0.5mm for switch) Operation travel: about 2.5mm Panel thickness: 1 - 10mm Crust and cap material: stainless steel Operate force:about 6N IP rating: IP65 Mechanical life: 5,000,000 times Electrical life: 50,000 times Operation Temperature: - 25 to 75 Degree