3/8 push fit x 1/2 BSP female. A typical use for this fitting would be to convert a barb and tail on the back of most stainless tap shanks into a 3/8 push fit. A simple reducer will then reduce the 3/8 pushfit down to your chosen pipe size. The picture shows the Tap Connector fitted to the shank of a tap and also a 1/4 reducer (not supplied).
Also available as 3/8 push fit x 5/8 BSP Female.
Please check the size of the thread onto which this will be fitted.