What is the pressure connection on the MasterFit / RetractoMaster?
The pressure connector on the MasterFit / RetractoMaster is actually a valve. This valve is similar to the style used on bicycle tubes and is referred to as a Woods valve or Dunlop valve. It can be inflated using a pump with a Presta valve fitting. The threads on the valve are 0.305 in (7.747 mm) x 32 TPI (1⁄32 in or 0.7938 mm pitch).