Russian prototype light bomber from the mid 1930s. Apparently it flew quite well but the project was cancelled before any production orders had been issued when the development organisation responsible for the design was closed down.
Modelling Note: there should actually be 7 pairs of cooling slots in each nacelle for the engines but due to the way the topology of the 3D model turned out I could only fit 6 pairs in. I may remodel this some time in the future (please PM if interested).
The spherical recess underneath the model is for mounting it on a 4.5mm BB.