Features:* 6.3mm Series Connector Screwdriver Bits* It is forged from high quality 50BV30 chrome vanadium steel, strong and durable.* The mirror finish is polished and chrome plated, which has strong corrosion resistance and is not easy to rust. Specification: * Material: Chrome Vanadium Steel * Color: Silver * Size: 1/4" square hole to 1/4"(6.3mm) 3/8" square hole to 8mm 3/8" square hole to 10mm1/2 "square hole up to 8mm1/2" square hole up to 10mm* Quantity: 5pcs/set* Use for screwdriver, socket adapter, step drill bit, chamfer converter Package content: 5pcs x converter Notes: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.2. Please allow slight manual measurement deviation for the data.