We have seen items sold from the USA to Sweden and Australia. The vast majority of our users are North Americans and Europeans. The most common warranty is a fitness warranty. You get the machine, you try it out and if it works, you pay for it. If it doesn't work to your satisfaction, you either send it back, fix it at your expense, or negotiate with the seller to have it fixed.
Many people offer equipment as is.
You should get all the details before deciding to make any purchase. If you are concerned about a purchase, talk to us. One other source of warranty is to work through either a reputable reseller, or the original equipment manufacturer. The supply of good used scientific equipment is scarce. This is a sellers market for most items, especially recent vintage hardware.