The Black Diamond: This model is extremely fast and light, uses 1/2A to C motors, although I'm a bit afraid to try a C in this little gem. I imagine it could easily reach 1200 feet.  It features streamer recovery. Added a lot of nose weight to balance this model, but now it flies very straight and true even in windy conditions. I was a bit concerned about cardboard fins, but they are very stiff and seem to work well (I just hope they don't get bent!) This rocket was later given my "Iris" modification, which extends the body tube about 5 inches above the streamer/parachute bay, and allows for a payload with an Altimeter One to measure altitudes. With the added weight, I needed a longer, 4-foot long, 2-inch wide streamer to slow it down some.  Not so easy to squeeze into a BT-20 body.  I had to lengthen the shock cord also, but it is still getting quite beat-up by its own recoil force. (Iris is named after the Greek god of the rainbow. She is a messenger of the gods, linking the gods with humanity.) If I were to build another one, I would split the launch lug and glue half of it further toward the nose. As it is, it wobbles on liftoff some while on the rod. I have only once tried this on a C motor, this rocket has flown higher than the Aon Center and the John Hancock Tower in Chicago, and the NY Times Building in NY, NY.