I can't find a reference to HS, but their tires labelled HD, or HD-V = high density, or high density Vectran, for their flat resistance layers.

HS may be "S"mart Guard, their thick flat resistant layer????

That makes sense. So is 420 vs. 348 about tread pattern? I'm trying to figure out if I'll be okay so long as I order the right size (700x35).

Interesting. I used your link and got the same product price. However, it must have geolocated my IP (I'm in Europe) and recalculated the shipping.

That's all I can figure that number must mean. See Marathon HS 420 vs Marathon Deluxe HS 420.

And as for "OK", depends on your goals I guess. I'm sure you'll get good flat protection and durability with any Marathon model, but many have noted that the bottom-of-the-line is rock-like in its weight.

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Undoubtedly that seller was smart enough to restrict his free shipping to US-only. I once made the mistake of not doing that, and sold a small item (a vintage Campy derailleur I think) to a dude in Australia, the shipping would have been like $60 for a $10-20 sale. I contacted him with as much groveling as possible, and he was nice enough to agree to nullify the sale for me.


But when I was researching schwalbe tires on eBay, I found that european eBay sites have much more variety and lower prices on schwalbe tires (in particular used, which are virtually nonexistent here in the US), so you shouldn't have to bother buying your marathons from America!