UTA - Adaptateur Universel - Product Reviews
If you're refilling using a bottle (ideally squeezable) or a running tap, it's fine. But the first time I tried pouring into it using a flask, the inflow was really slow, and would spill out. After some trial and error, I realized that the water pressure needs to be high enough for proper refilling. It worked when I lifted the flask up higher from the valve. But you need really steady hands to avoid spilling.
Love the UTA™ for so many reasons.
Very innovative and effective. This shortens our transition times and is super convenient in every application. Make sure it is all the way in the rubber adapter before you turn on the water or turn he bottle upside down. Buying one for every bladder we own.