Does anyone recognise this security fixing?

[Not-a-Farmer-Ben]

Hello.  I hope you don’t mind a non-farmer picking the brains of the farming community: I thought you might know about fences and security fixings. 
I need to undo the fixings on a mesh fence as it’s the only way to get access for a bulk delivery of building materials, but I can’t identify either the manufacturer of the fencing or locate a compatible driver bit to fit it.  Has anyone seen anything like this or recognise the manufacturer, whose name begins B, at a guess!  I've had to put in a link to my dropbox folder because I can't attach a pdf.

 

 

picture link here

Edited October 1, 2023 by Not-a-Farmer-Ben
edited to attach a link as can't upload a pdf