Description. 1.5mL 9mm Screw Neck Vial ND9 Caps with Septa 1. 1.5ml/2ml Short screw Thread ND9, wide opening, 9mm thread hplc vial with matched PP Screw caps ND9, PTFE/silicone septa & Micro-Insert 2. Short screw Thread ND9 vial is designed to ensure proper centering of limited volume inserts, eliminating missed injections.