Patented Features – Double-bearing grinding unit (reduces wear). – Drill tightening design with bearing device. – Adjustable trimming angle. Standard Accessories – ER 40 Collets, ranged from 12mm-26mm (15pcs). Optional Collets 8~11mm, 27~30mm – CBN wheel #200x1pcs (for High Speed drill). – 4mm and 6mm Hexagon (Hex.) wrench x 1 pc each