Uwell Popreel P1 Cartridge has a semi-shaded see-through window. The scale line on the pod allows vapers to clearly know how much e-liquid is left. The improved the pod’s leakage-proof and durability. After more than ten refills, the POPREEL P1 with built in 1.2ohm mesh coil provides good flavor. The Pro-Focs flavour adjustment technology perfectly restores the e-liquid flavour..