Features: brand new and high quality There are 3 different types sandblast/nickel-coated/chrome-coated, choosing according to your needs. If your screwdriver takes 1/4" bits and you want to use 4mm bits. This adapter is for you.or your screwdriver handle holder size is 1/4"/6.35mm and you want to use 4mm bits to work. Made of premium quality modified tool steel with high hardness. for Extra hard with natural finish for durability and strength. Exact fit machined precision tips for secure hold, for always stay safely. Screw driver bit adapter with magnetic, very easy to operate while working. Specifications: Material: Tool Steel Hex Size: 1/4" Length: 25mm/ 1.0 in Note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Screw Driver Bit Adapter