The Dakine Hydrapak design of the Replacement Reservoir is engineered to be durable and easy use. The Shape-Loc center baffle adds some rigidity to the shape of the bladder, which cuts down on shifting of water weight while you\'re in motion, and makes for a more resilient design. While the wide mouth opening and plug-and-play connecters make it easy to fill, drain, and clean. And, of course, it\'s BPA and PVC free.Key Features:Dakine x Hydrapak design,Low profile Shape-Loc center baffle,Plug-N-Play quick tube connector,Wide mouth opening allows for easy fill & cleaning,High-flow Blaster valve w/ shut-off,BPA and PVC free, FDA approved Polyurethane(TPU) material.