ANTIDOTE™ RESERVOIR FEATURES:1/4 turn - easy open/close cap, lightweight fillport, dryer arms, center baffling and low-profile design, patented Big Bite™ Valve, HydroGuard™ technology, PureFlow™ tube, easy-to-clean wide-mouth openingKEY PACK FEATURES:External fill, paddle holster, safety whistle, water-friendly materials, stretch overflow storage, capable of storing uninflated PFD