valve cap, small goods, which seem less useful, but basically it is essential, it is associated with the condition of the tires, if the air pressure inside the tire motorcycles we've fit or not.
close this valve can measure air pressure in the tires, if its pressure is less, then the color will be green, and if the yellow color will come down again, it is also nice, and close the valve is equipped security anti thief, if use hands, close this valve will not be open, and the price is just $ 5. cool it
