Easy to Use: A professional woodworking tool, the square hole drill adapter holder provides precise and smooth drilling by stabilizing the drill during operation. Compatibility: Suitable for hand electric drills; not suitable for bench drills or rechargeable hand drills. Size and fit: The fixing bracket supports the exposed clamping part of the electric hand drill with a diameter of 38 mm to 43 mm (1.50 inches to 1.69 inches). Please confirm size carefully before use. Material: Made of cast aluminum, wear resistant, hardness, sturdy and durable. Performance benefits: Improves hole accuracy, reduces drift, and provides a stable guide for square hole drilling. Use scenarios: Furniture making and cabinetry where precise square holes are required for connectors or hardware. DIY projects that require repeatable square hole drilling along panels or rails. On site woodworking tasks needing a portable, stable drilling guide.