It is a high-quality screw cap designed for secure solvent storage and handling in laboratory environments. Made from durable PPS material, it features a freely rotatable PTFE insert and two female UNF 1/4" (28G) threads equipped with integrated stopcocks for connecting capillary tubing with an outer diameter of 3.2 mm. An additional capillary connector is located on the bottom side of the lid, enhancing flexibility. The cap also includes a b.safe air valve with a service life indicator to ensure safe and efficient solvent management, especially suited for HPLC solvent reservoirs.