Create aseptic handling solutions for pharmaceutical, biotechnology and laboratory liquid transfer applications using Nalgene Filling and Venting Closures. Ready to accept additional fluid transfer components such as aseptic connectors and air vent filters, these port cap closures are available for use with Nalgene bottles and carboys with 53B or 83B closures, including pre-mounted lengths of platinum-cured silicone tubing for easy customization of bottles and carboys.