Aluminum Crimp Caps with PTFE/Silicone Septum. MOQ: 50 packs, 100pcs/pack; Aluminum Caps for 11mm 2ml or 20mm Crimp Neck Vials. Use Together with PTFE/Silicone Septa or Rubber Stopper. Color: Metal Silver. PTFE/Silicone Septum. Septum Size: 11*1mm; 20*3mm. Phone/Whatsapp/Wechat: +8618057059138.