They are made by JHP (Ducati Coventry) as well as being crash protection they are also quick release items, you can put a screwdriver through the hole to pull the axle out and the other side bung allows you to tap the axle out, both also help when refitting the axle
Thanks @simmytt - I think the former owner of my bike was a bit of a JHP fan, there are other bits from them on the bike.
