I think it is for traction kite’s only.
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RADSAIL BUGGIES. IF YOUR BUGGY HAS A DIFFERENT SET-UP. In addition, the bearings supplied in this set are 440 grade stainless steel. These bearings are suitable for use with standard 12mm bolt. The bearings supplied in this set are rubber sealed on both sides.
eBay
Radsails eolo project. New condition.
eBay