P.L.-Modellbau (or Peter Lorenz-Modellbau) has specialized in the production of a large variety of freight wagons, passenger wagons and some loco`s. They also produce a good variety of TT stuff, like containers, trucks, track side details, etc.
Flachwagen Samms-u, DB AG
Item # 31150
- Epoch V
- length over bumper: 131.5 mm
- 6 axle
- short coupling mechanism according to NEM 352
- short coupler head to exchange couplers according NEM 358
- comes with old BTTB style couplers
- metal wheels, isolated on one side
- plastic shunting rail imitation
- weight: 34 grams (almost bang on to NEM 302)
This model of an open flat bed wagon of the DB AG is of high quality, low rolling resistance and crisp detail print. The attached pamphlet warns you in multiple languages that this is not a toy

Here is the link to P.L.-Modellbau:
http://www.lorenz-modellbahn.de/indexnc.htm
Some technical info in german:
http://dybas.de/dybas/gw/gw_s_4/g453.html