MECCANIXITY 3mm to 3mm Inner Dia Rotatable Universal Joint Shaft Coupling L23 x D9 with Screws and Wrench for RC Model Pack of 4

What is this? Shaft fitting accessories to connect two different shafts and make them rotate together to transmit torque. Applied for RC model car, RC model boat, 3D printers, snow blowers, grinders and other DIY projects.What will I get?Color: Silver ToneMaterial: 45# SteelSurface Finish: ElectroplatedSection: OneSize: 23mm x 9mm/0.91inch x 0.35inch (L*D)3mm to 3mm(0.12inch to 0.12inch)Package Contents: 4 x Universal Joints, 1 x Wrench, M3*0.5 Fastening ScrewsIs there any advantages of the product?Made of 45# steel and with electroplated finish, the universal joint is sturdy and durable.Features with large transmission torque, high efficiency, stable transmission, small gap impact. Especially under the correct technical control conditions, it can access long lasting use.How to use it ?When you installing it, firstly install the two halves of the coupling on the two connected shafts respectively, then align, move and adjust the shaft to the correct place.What should I notice?In order to give full play to its function, please start the installation within the maximum allowable eccentricity range.