Needle Bearing, 10 roller for 10mm dia. piston wrist pin.

SkyHawk Gt5A and Gt5B 66cc engines have the best quality 10 roller piston wrist pin needle bearings for 10mm dia. wrist pins as standard issue.  

Some cheaper priced engines have the lower quality 9 roller bearings.  

Advantage: SkyHawk

Both 9 and 10 roller bearings are interchangeable on 10mm wrist pins except for the quality difference.  The higher priced 10 roller sold here-in is a premium choice.