The new 510-T Refillable Tank features a 360 anti-leaking design and is refillable making it highly efficient and cost effective. It holds 1.0ml of e-liquid and features 4 airflow holes for a smoother vape. The 510-T Tank also has a visible window which allows you to see how much e-liquid is your tank. The 510-T Refillable Tank provides a Mouth to Lung draw similar to how a cigarette is smoked.