The Boa Rotary Thread Rescue is the worlds first rotary thread repair tool. This tool replaces the need for kits of Taps, Dies and Thread files. The RTR is universal, fitting internal and external threads both metric and imperial. Suitable for use on all materials including plastics. The patented self-aligning profile easily enables re-dressing of damaged threads. Use with standard drills, die grinders or rotary-tools. The precision balanced diamond head is ultra-long lasting. Ideal for use on anything with a thread, the RTR1 is great for DIY uses including bicycles, auto, motorbikes etc., anything with a thread around the home or garage. Specification: Head Diameter: 9.5mm (3/8in)Arbor Diameter: 3.2mm (1/8in)Length: 50mm (2in)