Uxcell Magnetic Hex Socket Spanner Nut Driver Bit, 1/4-Inch Shank, 8mm, 20-Piece Product Name : Hex Driver Bit; Material : Metal Hex Socket Size : 8mm/ 5/16"; Hex Shank Size : 6.35mm/ 1/4" Overall Size : 12 x 40mm/ 0.47" x 1.57"(DH); Color : Silver Tone Weight : 346g Package : 20 x Hex Driver Bits