O Rings

Two sizes, both hard-to-find 90 durometer to limit twisting.

If you will be using Science Olympiad thrust bearings and 9.5" Ikara props, you need the large O rings

For F1D, EZB, Intermediate Stick, etc.
For F1D, EZB, Intermediate Stick, etc.
For Pennyplane, Science Olympiad
For Pennyplane, Science Olympiad