Carmex Tiny Tool Holder - Square Shank Holder to hold Carbide Small Boring Tool - 4mm Bore x 8x16The Carmex Tiny Tool Holder is a square shank holder designed to securely grip carbide small boring tools (Tiny tools) with a 4 mm bore, optimized for precision machining in tight spaces. Square shank design: Delivers a secure, reliable grip on carbide tiny tools while helping to reduce vibration for steadier cuts. 4 mm bore: Precisely sized to hold carbide small boring tools (Tiny tools) for accurate, repeatable performance. Compact footprint (8x16):