If anyone wants x-ring chains in 520 or 525 size, PM me, prices are ; X-ring chain 520- 120 link USD$37.95 X-ring chain 525- 120 link USD$39.95 Postage extra. Manufactured here in Thailand, they are Asahi brand, and are an impressive chain. I have only ever used the non o-ring chains they make, and on a 250cc four stroke dirt bike and I'm very impressed with them. Prior to using them I used RK (gold) brand chains, and noticed considerable stretch after only a couple of rides, even though I looked after the chain really well (cleaned, lubed regularly). In fact with this Asahi chain I've got on the bike now, I've started treating it like an o-ring because it hasn't shown signs of wear.