This is the GoMix/Fly Model 1/100 scale paper model of a Type IXC U Boat. Compared to their Type VII cousins, Type IXs are not that well represented in model kits - in plastic, there's an ancient tooling that was put out by Aurora, later by Monogram, the 1/200 Nichimo kits, and of course the little 1/700 waterline kit. With the boom in 1/72 scale subs, it's probably only a matter of time before we get a large scale Type IX, but in the meantime, this paper model is certainly one of the largest Type IXs you can build from a kit. It's sold in a 2 for 1 package that also includes a VIIC/41.
The kit as printed takes some liberties with color (not sure of that brownish color for below the waterline) but does build up into a nice looking model. As is typical with many paper kits, a certain amount of scratchbuilding is required. My periscopes and masts are plastic sprue - the railings are wire and thread.