Original Name / role No.: AR310447+AR310449Part location: Wheel hubs & external side of wheelProduct major functions & usage:1. Linking the CVD towards tires to be able to transfer the energy and lead a smooth drive.2. Lock and stabilize the wheel tightly.This product includes :Wheel Hex 2pcsWheel Lock 2pcsM4x2.5x15 Screw Pin 2pcsMajor features of upgrading for this part/product:1. Initial thickness is 4.5mm, this part is upgraded to 10.5mm for wider wheel track in order to run efficiently and much more stable.2. The hex are created to claw on the wheels tightly and firmly.3. Original capped design to avoid sand and dust during the drive.4. Special knurling process in the internal part for tight locking.