The only thing worse than having a flat tire is the patch you just applied didn't hold because there was an air bubble under the patch that prevented it from fully sealing This ITEQ Tire Patch Roller helps prevent this by allowing you to provide penetrating pressure over the patch as it vulcanizes and cures to force out trapped air bubbles that could compromise your patching job A few passes with the 6mm diameter wheel and firm pressure lets the gear-like teeth press into the patch and force out air while also more securely adhering the patch Package 1 x ITEQ 40mm Tire Patch Roller Used for rolling tire and tube patches adhere fully during repairs, ideal tire repair tool for cars, motorcycles and bicycles DEFINED TEETH - Deep-cut and clearly defined gear-like teeth provide more penetrating pressure to remove trapped air Wooden material handle makes it durable , portable and comfortable to use Wheel Size : 38 x 40mm/1.5 x 0.36" (D*T) Handle Size : 115 x 28mm / 4.5 x 1.18(L*D)