Dating back to the 1980s as I recall, this is a rather nice rolling road that works for both diesel and steam locomotives.
Hosues in a wooden base, a length of track has been bent (in a press presumably as it's very neat) so one end can support a non-powered bogie or tender with pickups. The lower level is home to the rollers - brass with plastic ends. These only power one side at a time so you have to flip them around to make sure both polarities are delivered to the model. Knowing how the loco picks up and from where is a bit help here. Foam strips hold them in place and stop too much wobble. These have aged, but I'm pretty certain something suitable can be bought from a DIY store.
While I own a Bachyrus rolling road, which allows for multiple gauges, most construation will be in OO, and this is a lovely thing and still workd perfectly. Price, £20 from Stafford second hand still and worth every penny.