Blue 9-425 Open Top Ribbed Screw Cap with 9mm Red PTFE/White Silicone Septa 1mm Thick PRE-SLIT (Mercedes Shape). 100pcs/pk. ① Compatible for short neck ND9 vials (12*32mm) most common used for HPLC/GC. ② Ribbed cap makes it easier for autosampler to capture. ③ Y shape pre-slt is special for thin or blunt needle while injection, and can also avoid