Black chrome finish is corrosion resistant and visually distinctive|Ratcheting spline box end is countersunk for easy application to the fastener|Spline design also helps prevent rounding of corners and other fastener damage that could lead to Foreign Object Damage (FOD)|Spline design enables the wrench to contact conventional fasteners away from the corners, which help apply force over a large area helping to reduce risk of fastener rounding|Spline design was created for use with specialty spline bolts which are used when weight and size of bolt heads must be minimized