1. Invisible valves minimize the volume of valves on wheels, to improve the whole balance and the gross appearance.
2. The stem is not on the body of valve, but designed as an extender(Exb-3-Cu). To inflate your tire, you just remove the dust-free cap with a coin and install the extender. Then you can inflate through the extender just as usual way.
3. The design of invisible valves is popular in Europe for high end users, with high quality and beautiful looking demand.
4. SE-452-A-Cu & Exb-3-Cu is made of brass.
5. Can be made with brass as well.
6. Rim hole fit : 11.5mm.

**SE-452A is newly designed, with different cap and all-in-one extender. The all-in-one extender is used to remove the cap in one end and installed for inflation in the other end.