This is a compact structure, flexible movement and durable in use omnidirectional Mecanum wheel for all types of smart robot cars. Compared to other common wheels, this Mecanum wheel can allow your car to achieve 360° movement for faster travel in a variety of environmental terrains. It defaults to the cross-axis mounting port, which can be plugged into the building block servo and building block motor, making it easy to build an Omni-directional mobile smart building block car. Four mounting adapters will be provided for connection to TT motors. In addition, we will also provide some tutorials as a reference, which contains a variety of mobile control methods such as, left and right translation, large-angle drift, oblique 45° direction movement, square track movement, etc.