BGM says:
"Part of the bgm air filter box (item number BGM4488). Is made in Germany and can be used to modify originakl air boxes to breath more air.
The diamter of the weld in part is the same as the one of the hole in the frame."
Product safety information
Manufacturer information:
Scooter Center GmbH
Kurt-Schumacher-Str. 1
50129 Bergheim-Glessen
Deutschland
info@scooter-center.com
https://www.scooter-center.de