The innovative Omega HydroTanium Reservoir is built with ruggedized polyurethane so that it's even stronger than before. A wide 3.5-inch opening with a tethered cap makes it easy to fill and clean. Plus, combined with a super effective anti-microbial film, these reservoirs last longer than ever. It includes a drinking tube and the highly drip-resistant Big Bite Valve. Please contact us if you have questions about reservoir fit.