Low quality product. This is not the type that uses the connector's inner wire to push the OEM valve core. This requires complete removal of the OEM valve core, resulting in the cheap, low quality gaskets on this product not properly sealing the Schradr OEM valve stem. This means that adding air or measuring the existing pressure is not possible as the seals on this product restrict air exchange and therefore the air pressure cannot be set accurately. I do not recommend this product at all.