Sometimes you come across a piece of equipment that you know is British and military, but beyond that you cannot find any information about it at all. Tonight is one of those little items, a manpack antenna carrier:

This little pouch has a label sewn inside that has a British NSN number, as well as a description and a manufacturer’s logo:

PRI stands for ‘Police Resources International’, a manufacturer that produces webbing and tactical gear in the UK for both police and military contracts. Beyond this though I do not know exactly what radio this pouch goes with, and so far all my research has drawn a blank.
The rear of the pouch has a tab that allows it to be attached to a MOLLE system:

Again I am not sure what the four black metal eyelets are for. There are two tabs at the top to access the inside of the pouch with a press stud. Pulling the tabs opens the pouch easily:

If you do know what this pouch is actually for, please get in contact as I’d be fascinated to know. Its obviously to carry a coiled up aerial, but which aerial and for which radio I can’t say.
It’s for a Bowman manpack radio GPS antenna as seen here to the immediate left of a PRC 355
http://www.armedforces.co.uk/army/listings/l0102.html
Here’s a better image
https://images.app.goo.gl/cttE9Bvi8QvjvtAj6
Says “GPS” on the label and the shape looks about right for a GPS antenna.