Nimbus RDA Rebuildable Dripping Atomizer This RDA has two ground posts and one positive post allowing you to build single or dual coils. The Nimbus RDA Rebuildable Dripping Atomizer is manufactured from stainless steel and brushed for an elegant matte finish and also available in a polished stainless steel. Features a single air hole located near the bottom for increased airflow performance. The Nimbus rebuildable atomizer includes a small screw driver, Allen wrench and two replacement O rings. The Nimbus Atty is a perfect mid-range and moderately priced RDA / RBA dripping tank compatible with your Mod to meet your exact vaping needs.