SpaceBall 4000 FLX
The SpaceBall 4000 FLX is a 3D control peripheral sold by 3Dconnexion.[1]
It was replaced in the lineup by the SpaceBall 5000.
It connects with RS-232.
Units were sold under the Labtec brand and the Spacetec brand. They were later sold under the Logitech brand.