These are the standard nylon gears that go into the cyclone 3000w and 4000w motor planetary gear reduction gear box. Be aware that older motors used gearboxes with 30 teeth. The 22 tooth gears are NOT compatible with older 30 tooth gearboxes.
These are a wear item. One should expect to replace them periodically. Typically we get 18-24 months of use of of a set before they start loosing teeth, sounding chunky, quickly failing and requiring replacement. Heavy, more powerful bikes, in hilly environments, accelerated more quickly, will have require more frequent replacement.
Lube with a plastic specific grease to extend service life. Standard bearing grease may degrade the plastic and lead premature deterioration and failure.
No warranty what so ever expressed or implied.