Descriptions: <br> It's changeover axle sleeve for 3.17 motor axle converted to 5mm motor axle.so that you can install the 5mm motor gear.<br> CNC Machined,durable and lightweight.<br> Upgrade parts,easy to install and remove.<br> Inner Diameter:3.17mm <br> Out Diameter:5mm<br> Length:12.2mm <br> Color: Silver<br> <br> Package Includes: <br> 3 x 3.17mm to 5mm shaft adapter<br>