<p>Size :ER11 A - 4pcsFeatures:1. Built in self-Release design and tools will never get stuck in holder.2. The metal collet nut has a strong clamping force and is not easily deformed.3. Precision machine tool accessories grinding of this product may produce dust during using.Specification:Material: Cast SteelModel: ER11-AStandard: MetricThread Size: M14Overall Size:19x14mm/ 0.75”x0.55“ (D*H)Thread Pitch: 0.75mm / 0.03“Hex Width: 17mm / 0.67”Hole Diameter: 9mm/ 0.35“After-sale service:Feel free to contact us with any product issues.We will do our best to provide you with a solution or refund service.</p>