Available in 8 models with heavy-duty, 1- and 2-stage configurations, NG Series incorporates double seal with single distance piece located between 2 sets of seals on each piston rod. Materials maximize performance while minimizing maintenance. Also offering 8 models in 1- or 2-stage configurations with double seal, NGS Series handles sour gas that contains up to 8% dry H2S. Select parts follow NACE guidelines in all gas-containment areas, and steel wrist pins ride on steel needle bearings.