A while back I got the Ballistic Crosshair and noticed that the box and stems said SI BALLISTIC CROSSHAIR VØ. On one of the Facebook groups, someone posted it as Crosshair V8. I hadn't really looked into it, but a google search for 'Crosshair V8' only returned ebay sellers and Fuse lens knockoffs, while 'Crosshair VØ' returned the SI page even without mentioning anything about glasses of Oakley (leading me to believe there was some meta data hidden somewhere for that search term).
I figured it must be some sort of tech term like HALO, so I did stumble upon this:
A device of the Swiss artillery to measure the muzzle velocity (VØ). The sensors were mounted on the barrel of the gun. It was used in the forts and in the field. The muzzle velocity of a caliber 10.5 cm grenade was 700 - 800 m/s. The equipment is outdated and no longer used. Newer devices comprise of a Doppler radar. Fire control center of the disused military fortress Furggels on St. Margrethenberg, Switzerland, Dec 16, 2012
https://www.flickr.com/photos/kecko/8291565515/
So a pair related to Ballistics and impact protection, it seems that would be a good match.