The Quad Flex RDTA can be refilled by 2 different ways: 1. Fill the tank through the bilateral e-liquid holes of RDA deck well using a syringe dropper;
2. You can also drop the RDA top up so it is still touching the tank at a 30 degree angle and drop, drip or pour directly into the Pyrex tank.
3. For RDTA,We suggest 2.5-3.0mm coil(inner diameter)