• The contact key can be used to open and close an electrical circuit. The contact key is mounted on a 3" x 4.5" x 3" black acrylic base and has two binding posts to connect to an electrical circuit. The key is made from plated metal with an insulated button.
• Built with two binding posts for connecting to an electrical circuit.
• The large button is used to open and close the circuit and is made of an insulating material

The contact key can be used to open and close an electrical circuit. The contact key is mounted on a 3" x 4.5" x 3" black acrylic base and has two binding posts to connect to an electrical circuit. The key is made from plated metal with an insulated button. This tool is often used with a Wheatsone Bridge.