These are so much easier to use that the water bottles with the pop tops. I started using the belt for running this last year, I love the belts, but was having a hard time pulling up the pop tops, closing them all the way (because if you don't they leak on you as you run). These tops are great. This is the best price I found and they shipped quickly.
I just got these and tried them out for the first time. On inspection, they seem to be the same as the originals but with a slight modification to the lid. However, they are make a world of difference. No longer do I have to waste time and energy laboriously pulling up the top and smashing it down, nor do I have to worry about leakage from the side of the tops. The quick shot top dispenses at a gentle squeeze and does not leak when I am running. BIG improvement. I don't have weird colored underwear after a long run from Gatorade leaking out of my bottles. My only dig on the bottle is that the 10 oz size sticks a bit in the holsters and takes some pulling to get out. Really great product over all.
My wife uses her nathan 10 oz bottles in all her marathons. She's doing her 50 states now, about half way through!