Cup holder insert for a Topside Dual mod. Few mm extra either side and filleted edges for easy insertion while driving.
The cutouts are designed so it can fit into cup holders in a Volkswagen Mk5/6 Golf and Jetta. They may also come in useful for other cars though.
Massive thanks for user ayan4m1 for including the DXF outline of the mod in his holder he designed (link below)