Specifications: square head across flats size are 1/2 inch(12.7mm), 3/8 inch(9.5mm), 1/4 inch(6.35mm)
Shank diameter: across flats 6.35mm hex shank, double R groove
Shank is across flats 1/4 inch(6.35mm) hex shank.
Usage: Screwdriver driver socket bit adapter
Please allow 1-3cm differs due to manual measurement.
Due to the different display and different light, the picture may not reflect the actual color of the item. Thanks for your understanding.