This is 7×1 BO Motor’s Wheel. Screws can be fitted into the axil socket mounted from the front for keeping wheel in place. This is a great for your RC car projects. Wheel for standard low cost DC Hobby BO motor for robotics. Specification: Size: 7×1 Color: GREEN Very smooth universal wheel. Made with high quality material. Durable and long lasting. Package Included: 1 x 7×5 BO Motor’s Wheel Red/Green