Dunlop valve
The Dunlop valve, is a type of pneumatic valve stem in use—mostly on inner tubes of bicycles—in many countries, including Japan, Korea, India, Pakistan, Sri Lanka, most European countries, and a number of developing countries. The Dunlop valve has a wider base than a Presta valve, similar enough in size to a Schrader valve to use identically drilled valve holes in rims, but it can be inflated with a Presta valve adapter. The inner mechanism of the valve can be replaced easily, without the need for special tools.
The Dunlop valve originally used a tight rubber sleeve which had to be forced open by air pressure while pumping, but modern Dunlop valves use a different plug using either an internal ball bearing or a spring-loaded rubber plug that is unseated by pumping, making the valve as easy to pump as a Presta valve.
The inventor was C. H. Woods. It superseded John [Boyd Dunlop|Dunlop's] original valve for pneumatic tyres.
Dunlop valves are uncommon on bicycles in the US, where either Presta or Schrader valves are used.