There are two types of tyre valve connector. It is therefore important to specifiy whether a closed or open end type is required.

Closed End - used when air is suplied directly from a main air line (i.e. compressor or air receiver). A non-return valve unseats on connection to the tire's valve allowing air to flow into the tire.

Open End - used with PCL MK3 tire inflators, ACCURA tire inflators and portable gauges. This connector has a pin which unseats the tire's valve when in use.

There are basically two sizes of tire valves in use.

8v1 - is the standard Schrader car tire valve size found on the majority of tire valves. It is approximately 8mm in diameter.

12v1 - is a large bore tire valve found on some aircraft and large volume tires (earth moving equipment, heavy plant, etc). It is approximately 12mm in diameter.