Can wrench

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Can wrench: a tool used to open telephone distribution terminals, also called telco cans or demarcation boxes. It has two ends: a 7/16-inch hex socket for recessed closure fasteners, and a 3/8-inch hex socket for binding posts. It’s sometimes known as the 216C Bell System tool. Many are insulated for electric shock protection. The sockets are thin-walled to fit into the tight recessed openings found on telco cans and demarcation boxes.