Stanley Proto J47000CF 1/4-Inch Drive 6 Piece Crowfoot Wrench Set Crowfoot wrenches are used in hard to reach, restricted access situations where a standard wrench or ratchet cannot reach Anti-Slip Design open end (ASD) The arched surfaces are designed to spread the contact forces over a greater area Broad size range ensures the right tool for the application will be available Typically used in lower torque applications