the radio, as seen in rp_industrial17_v1
The "Magic radio" as it is known, is a radio present in the maps rp_c8, and rp_industrial17 (and many of their variants).
It is unknown who originally discovered the radio prop's properties, though some people credit it to either Bob Good or Johnny Nutmegg, as it was seen commonly used starting after 2015, when both minges were active.
The radio is known to have odd physical characteristics, with tilting up or moving it to the side causing players to be pushed through walls.
Many server admins will delete or freeze this prop to stop solo-minges from griefing into the nexus, however there are still many methods that aren't easily blockable, and most maps for the gamemode made after 2018 don't have the prop anymore.