(1) Dual Wheel Flexible Valve Extensions Provides easy access to the inner dual tire found on campers, recreational vehicles and trucks. Fits standard valve cap threads. Comes with clamp to secure extension to wheel cut-out. (2) we have been manufacturing tire valves extension for many years. (3) our products quality is high and price is competitive. (4) our delivery time is timely and our service can let you satisfied. (5) we can supply to you free sample.