Comprehensive Kit Includes: This set comes with 4 units of 5mm flange coupling connectors, 4 fastening screws, and a handy mini hex wrench, providing everything needed for a seamless installation and secure fitting. Precise Dimensions for Perfect Fit: Each coupling features a cylinder outer diameter of 10mm (0.39 inch), height of 10mm (0.39 inch), inner diameter of 5mm (0.2 inch), base diameter of 22mm (0.87 inch), and a base height of 2mm (0.08 inch), ensuring a snug fit and optimal performance. Ideal for Model Shaft Connections: Designed specifically for RC model motors and various mechanical applications, these couplings ensure a reliable connection and enhance the operational efficiency of your projects. Durable Construction: Made from finely plated metal, these shaft couplings undergo rigorous heat treatment followed by electroplating, which enhances their durability and resistance to wear and tear. Functional Design: These special couplers are crafted to fix one shaft to a plane, allowing for easy installation of other components on the shaft, thus simplifying assembly and maintenance tasks. Colour:Silver Material:Metal Package Contents: 4 * 5mm Metal Flange Shaft Couplings Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.