O Rings
Two sizes, both hard-to-find 90 durometer to limit twisting
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one dozen, small O rings

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For F1D, EZB, Intermediate Stick, etc.

one hundred small O rings

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For F1D, EZB, Intermediate Stick, etc.

one dozen large O rings

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For Pennyplane, Science Olympiad

one hundred large O rings

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For Pennyplane, Science Olympiad