This model (they come as packs of three) represents a 3 bar slab wagon. While not an exact copy of a specific prototype, wagons similar to this would have been found in many rail served Welsh quarries being used for moving large chunks of slate around.
Each wagon consists of five parts; the main frames and four axle retainers. The four axle retainers are provided on a single sprue and need separating with a sharp knife before assembly (a spare is provided on each sprue).
The wagon can be painted using most common modelling paints (I use a mixture of Humbrol, Model Color, and Tamiya acrylics). To complete the wagon you will need to add wheels and couplings. The wagon was designed to take 5.1mm wheels from Parkside Dundas, specifically PN62, and the model includes slots in the buffer beams designed for use with Greenwich Couplings.
Note that the photos currently show a prototype print. The current model has crossbars which are 2mm longer to better represent the majority of the wagons used as inspiration.