Superior Electric S4-TL Universal 4 in 1 Drill Chuck Key for Drill Chucks (Large) - Pilot Shank 3.9-6.0-8.0-6.9

Features: Essential power tool accessory for hand-held power & cordless drills, drill presses | One tool with 4 key sizes for tightening and loosening chuck | Drill without properly tightened chuck is virtually worthless - always keep extra key on hand | This part is compatible with: Variety of power and air tool chucks | Specifications: D1: 16.3mm (0.642"), 17.4mm (0.685"), 21.2mm (0.835"), 16.2mm (0.638") | D3: 3.9mm (0.154"), 6mm (0.236"), 8mm (0.315"), 6.9mm (0.272")