Use the Nalgene DS2153 Polypropylene 70mm Fluid-Transfer Closure with 500-, 1000-, 2000- and 3000-mL Nalgene Mason jars (B6880) for fluid transfer in the lab or field, or with Nalgene straight-sided jars (B6700, J1085 and J1085A) with 70 mm neck finish. Containers sold separately. Use for siphoning, evacuation, bleeding of fluid lines, collecting samples, transferring reagents. Two vent ports, molded into top of closure, connect to external fluid source and to vacuum or pressure pump with 1/4-in. I.D. flexible tubing, e.g. NALGENE 180.