Beautiful and Quality switches, Contactors and pins made from Copper, not iron will not melt. 

• All the switches have 3 terminals, the bronze colour connects the internal light
• Panel mount diameter: 20mm 
• Overall dimensions: 30 x 23mm (Height x Diameter) 
• Switch Rating: 20A 12V DC
• Light Rating: 5-16V DC
• Unfortunately these will work with 5-16V only, otherwise light will burn-up from overvoltage

How to connect?

• Check the second picture for diagram
• Basically the "silver" pins are the contactor (positive (+) wire) and the brass pin goes to minus (-) to supply the internal light with power, when contactor is switched