This Bottom Bracket Lock Ring Spanner is an essential tool for any cycling enthusiast. It features a hook that can be used to remove fixed gear flywheels and lock rings. The spanner has an overall length of 155 mm (6.1 inches) and is made of durable steel. It is compatible with lock ring sizes of 15 mm and 16 mm, with a greatest width of 45 mm (1.77 inches) and a thickness of 4 mm.