This is an injection-plastic aircraft model kit.
From the manufacturer:
The SG-38 glider became a standard training machine for the NSFK which was mass produced by several factories. It could also be home-built from drawings sent by post. Production was not restricted solely to Germany and the basic design went on to be built throughout the world, making it the most widely-used training glider ever known.
This kit consists of parts molded in grey plastic and includes photo-etched parts and decals.