Use the 70 mm Thermo Scientific™ Nalgene™ Polypropylene Liquid Transfer Caps for liquid transfer in the lab or in the field. Cap is compatible with Nalgene Mason Bottles (Item No. 2115), 125 and 500 mL Nalgene Straight Bottles (Item Nos. 2116, 2117, 2118, 2119) and sold separately. These caps are used for siphoning, draining, venting liquid lines, collecting samples, or transferring reagents. Two vent ports are injection molded into the top of the cap (outer male ports only; no internal dropper connection) and can be connected internally to a vacuum or pressure pump with 1/4″ ID hose (tubing sold separately)