I bought one of these cages and it hold my bottles securely without rattles, It just works really well so I bought another ( enough said).
I admittedly only use this on my road bike but I would happily use it on my mountain bike
One of the best bottle cages I have ever owned! Entry is easy and it has a confidence inspiring 'notch action' so you know that the bottle is in. The carbon wings are springy holding the bottle well and its never failed me yet. I race XC so I need a bottle cage that works, you see so many stray bottles on the floor when racing - none of them are mine ;). Racing flowy courses to gnarly drops, steps