I can't vouch for anything Guyot designs makes for any other company, even nalgine but I can vouch for their bottles from their website plus their customer service has been beyond outstanding. I have many 32 oz bottles from them including a free one because they shipped one that had a dent in it plus they sent me a bunch of those plastic spill inserts for free. They have made a life customer from me due to the way they treat the customer and such a outstanding product. I can put any cap on mine that will fit a nalgine standard threads, I use my combi water filter on it, I use a steripen in it, I've boiled water in it and keep one in my work backpack, one in my BOB and one for normal traveling. I won't buy them from the store, I go and buy them from the website due to the great customer support and how they stand by their product, a few dollars savings isn't worth it for the support giving. You can't go wrong in my opinion, and I believe they have done Izzy right in the past from a dented bottle if I'm not mistaking.