The Assenmacher Specialty Tools 10mm Bypass Wrench, No. BY10, is designed to access bolts and nuts by going around obstructions that would normally be in the way. The BY10 is able to access hard-to-reach places and provides leverage to 3/8" tools. It is ideal for various CASE Construction Equipment and Chelsea-Allison PTOs as well as any other applications requiring a 10mm. Made from forged steel. Also available in 13mm (No. BY13) and 14mm (No. BY14).