Horizon ARCO Sub-Ohm Tank With Resin Drip Tip The Horizon-Tech ARCO Sub-Ohm Tank has more to offer than just its good looks. Each ARCO Sub-Ohm Tank comes with a sexy vacuum plated glass and a spare clear glass tube, capable of holding 5mL of E-Liquid. Horizon has produced a coil head that is the first of its kind. The coil head is filled with flax paper and cotton. The flax paper is made out of natural flax fibers and can hold more e-liquid than cotton. This means your coil gets plenty of liquid and can optimize your flavor. The fiber stretches with liquid the more you use it, so the flavor gets better over time. The flax paper has a higher burning point when wet which helps prevent dry hits.