Universal knitting key for fireman fitting

A tricoise key is a tool that allows to tighten pipe fittings, including fireman fittings. A fireman fitting consists of a threaded strain without a lock (male or female) and a half-threaded fitting with a lock. It may have other functions (screwdriver, opening of various devices).Correspondence of connection dimensions in mm and inch: - diameter 50 mm (inside) / 60 mm (outside) = 2 inches- diameter 60 mm (inside) / 70 mm (outside) = 2 ¼ inches- diameter 66 mm (inside) /76 mm (outside) = 2 ½ inches- diameter 80 mm (inside) / 90 mm (outside) = 3 inches