National Scientific 8-425 Screw Thread Assembled Vial Kits 2 mL, Clear Glass, PP Black Cap, PTFE/Silicone, 8-425 Standard Opening Assembled Vial Kit - 100 ea. Specifications. 163728: C4013-15A: $91.25: PK: 845-50590: 2 mL, Amber Glass, Black Flangeless Cap, PTFE, 8-425 SO Assembled Vial Kit - 100 ea. Specifications. 163733: C4013-19A: $66.25