This is a standard 30mm button that will fit in a 28mm mounting hole.
It features a concave plunger and includes fixing ring and microswitch.
Product Features:
*Mounts into wood or metal control panels
*Ideal for use within 3/4" wood control panels
*Microswitch reliability tested to 10,000,000 cycles
*Vertical attached microswitch with .187" (4.8mm) terminal
*Durable nylon material
*Concave plunger design
*Mounts in 28mm hole.