"Chrome Vanadium Steel for Extreme Durability Lobular Design - Our lobular design reduces the stripping of the corners of the nut. Fasteners are driven on their flat sides instead of their corners. Extra strength magnet secured in place with splined brass bushing. Results in greater retention of your fastener, making your job faster and easier. 1/4"" power hex shank Bulk - Sealed plastic bags with clearly marked labels. Nut setters also available carded and in hex jars."