Originally Posted by
nfmisso
This is an Aria brake for a tandem:
Arai Drum Brake Tandem Touring Bicycle Bike Drag | eBay
Please note that Aria is a Japanese company that has made dozens of different drum brakes for bicycle and similar applications - only one model was intended to be a drag brake for tandems. Contrary to reiker's opinion, the tandem drag brake is amoung the least common Aria produced for the world market, which is why the price is high, and it is no longer made.
If I'm not mistaken, the Arai drum brake usually used for tandems was originally a moped brake.