Its shneider, telemechanique component which I copied and share with all you guys.
Emergency Stop Switch - Schneider Electric & Square D - 22mm diameter, Turn to release, XAL-K174
Now available from RS Components, the Schneider Electric emergency stop switch is manufactures with polycarbonate enclosure with an ingress protection of IP65Red.
Emergency shutdown switch features
* Red in colour to enhance safety
* 40mm diameter latching push button head
* Body dimensions: 68 x 68 x51mm
* Knockouts: 2 x 20mm (side); 2 x 19mm (base)
* Body Material: Polycarbonate
* Contact Configuration: 1 N/C
* Depth: 53mm
* Head Diameter: 40mm
* Height: 68mm
* Series: XAL
* Width: 68mm