I use these motors in a single mount for scratch built rockets up to BT-56 size and in a dual mount in BT70 and 80 tubes. They are easy to light and give a nice long burn. Against a cloudless sky with calm winds it is a great spectacle to see the tower of white smoke. Plus with the great pricing from HobbyLinc, I can try several different designs without having to worry about breaking the bank. One small con with these motors is that you cannot expect to get the high velocities at burnout like you can expect from staging 2 'D' motors as the thrust is lower. With fat rockets like the BT80 designs, you will reach apogee shortly after the thrust phase is done unless the day is calm and you launch vertical. Then it will just seem to hang on top of the smoke column which looks very cool. On days when you need to angle away from vertical however, I recommend dropping down a delay category.

This is our favorite motor for the Estes Eliminator XL. It sends it to 1400 feet. At the elevation and speed of this rocket the 8 second delay works well. Most other rockets we launch on E's we use the 6 second delay (E9-6)

Provides nice liftoff optics for a larger rocket, but a bit pricey.