2 PCS 12" and 16" Flexible Extention Screwdriver Drill Bit Holder with Magnetic Quick Connect Drive Shaft Tip 1. Length: 12" and 16" 2. Connection hex shank drill site size 6.35mm (1/4) 3. Connecting parts of the batch Hex size 6.35mm (1/4 4. Flexible out shield protects your hand while inside shaft rotates. 5. Bends,twist and turns to use drill into tight and confined spaces.