EASILY ATTACHABLE: Fits drill chucks 1/2 inch for a secure connection. COMPLETE SET: Includes a removable 6mm pilot hole drill bit. COMPATIBILITY: Works with Amtech Bi-metal holesaws from 14mm to 30mm. POWER TOOL ACCESSORY: Designed for use with power drills. ENHANCED PERFORMANCE: Arbors help reduce pressure on pilot bits and create cleaner holes by securing the holesaw.