to counterhold the sprocket for removing the lock ring | spring loaded opening mechanism for easy use side-lever enables one-hand operation | suitable for sprockets from 10 to 19 teeth for 5 to 12-speed sprockets | suitable for Shimano, SRAM, etc. material thickness: 4 mm | length: 300 mm handle material: polypropylen | material: carbon steel | surface finish: satin chrome plated