This is a panel mount, spdt (noramally open contact set AND normally closed contacts) relay from Struthers Dunn, Made in USA. New old stock.
Solder lug terminals and built in screw for mounting on a panel or bracket.
Load Rating: 15Amps for 120 to 240Vac, 10Adc at 28Vdc.
Control with 120Vac low current switch. Isolated coil (from contacts)
I have several available here.