Estes EST3179 Laser Cut Centering Rings & Paper Adapters (4 pc)

Includes 26 Centering Rings in 5 different sizes. BT5, BT20, BT50 and BT55. Perfect for making your own engine mounts!26 Centering Rings8 each. BT5 to BT20.4 each. BT5 to BT50.8 each. BT20 to BT50. 2...

The Estes B4-4 is single stage engine designed for model rocket flight. This engine is a standard engine designed for flights in rockets weighing less than 3.5 ounces, including the engine. Each...