Buy THC Vapes UK: Pre-filled THC oil cartridges are mini vape tanks filled with weed oil, sometimes referred to as hash oil. The tank contains a small coil which is powered by either a standard weed pen, a 510 thread battery, or a proprietary pod style device. Most THC cartridges contain a gram (1 mL) or half gram (0.5 mL) of THC oil, usually extra