10 Centering Rings:

Heavy duty rings for centering tubes BT5 tubes into BT20 tubes or as an engine block for A, B, & C engines

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.