1. With the flexible hose, you can work in tight spaces. Thick pipes and extended mounting rings enhance the sturdiness and durability of the flexible shafts. 2. No specific interface specification is required for the electric grinder, as long as the electric grinder or drill is compatible. The 6.5mm size allows for easy installation by attaching the power connector handle to the grinder. 3. Installation is convenient and simple—attach the connector handle to the electric grinder. The shaft connector must be used with an electric grinder. 4. Extends power tools for grinding small workpieces in confined areas. Specification: Material: Metal. Shaft Installation Instructions: 1) Remove the rotary nut from the collet and the top cap from the rotary tool. 2) Slide the collet nut onto the shaft core. 3) Insert the shaft core into the neck. 4) Tighten the collet nut securely to ensure the shaft core is firmly held in the tool. 5) Screw the shaft connector onto the rotary tool to ensure the shaft core is fully engaged. Drill Bit Installation Instructions: 1) Insert the included L-bar into the hole on the side of the arbor clamp. 2) Unscrew the clamping nut from the shaft. 3) Insert a drill bit (not included) into the clamping rod. 4) Tighten the clamping rod nut. 5) Remove the L-bar. Package Contents: 1 flexible shaft, 1 handle, 1 key.