eBay

This listing is for a NEW OEM Polaris YOUTH ATV standard bore ring set. The part number for this part is 0450025 and the Alpha part number on the package is 13011-111-000.

Looked the part number up online and found that this will fit the following machines, may fit others too

A01EA05CA SCRAMBLER 50 (2001) (A01EA05CA)
A02EA05CA SCRAMBLER 50 (2002) (A02EA05CA)
A03EA05CA/CB SCRAMBLER 50 (2003) (A03EA05CA/CB)
A04KA05CA PREDATOR 50 (2004) (A04KA05CA)
A05KA05CA PREDATOR 50 (2005) (A05KA05CA)
A06KA05CA PREDATOR 50 (2006) (A06KA05CA