Stamped in the metal on the screw-side of the switch.
Scratched in the metal on the side opposite the screws.
overall: 1 3/4 in x 1 5/8 in x 5/8 in
The object consists of a metal body with a threaded part that extends outward that holds the push button. The contact section is made with nine layers of phenolic that hide the mechanism. The switch is rated at 1 A, 125 VAC. "UND. LAB. INC. INSP." is stamped on the screw side of the body. The item was manufactured by "A. H. & H."