The Park Tool SR-18.2 Sprocket Remover/Chain Whip is designed specifically for 1/8" single-speed sprockets and cassettes. Heat-treated for durability the SR-18.2 also includes a 1" box end wrench for multipurpose use. Features: Chain whip fits 1/8" sprockets and cassettes Heat-treated steel with molded handle for comfort Only for 1/8" single speed (for 3/32" single speed, see SR-12.2) 1" (25.4mm) box end wrench 35.5cm (14") tool length