Source Outdoors Military Universal Tube Refill Adaptor (Green)
UTA provides on the move hydration system refills right through the drinking tube. Fit the most widely used water bottle and spigot sizes as well as Water Buffalo field units. Mates with Source's QMT "quick-connect" system for instant, "click in, click out" operation. Fast fill-ups even with unpressurized water sources. Visual fill indicator. Optional accessory  COMPATIBLE ONLY WITH SOURCE HYDRATION QMT SYSTEMS