26 Centering Rings:

    8 each. BT5 to BT20.
    4 each. BT5 to BT50.
    8 each. BT20 to BT50.
    2 each. BT20 to BT50 - 1 inch long.
    4 each. BT50 to BT55.

Estes model rocketry is recommended for ages 10 and up with adult supervision for those under 12. Unless otherwise specified, all models require assembly. Tools, construction and finishing supplies sold separately. In order to launch, a launch system, model rocket engines, starters and recovery wadding are required - sold separately-unless otherwise specified.