The 601-AC push button features an ex copper finish with a Halo-lighted center push button insert. This push button a portion that must recess into the surface it is mounted to. It a 5/8-Inch -LRB- or 16 mm -RRB- diameter hole to be mounted properly. The plate of this push button flower on the surface, while the rearward portion of the push button recesses into the hole.