It's gonna be a Nalgene, I think. The one I want is microwaveable and squeezable. We shall put a ComoTomo nipple on it. Finding the right components might be hard, though. The little ringy thingy that screws the nipple part onto the bottle is 3" wide in ComoTomo bottles. Good news is, you can put your hand right in, no bottle brush needed, bad news, they only hold 8 oz. Refilling is a PITT. Any other suggestions of sports bottles to work with a nipple? The nipple gasket takes the diameter down to 2.55"