PUMP-3: 12V DC: Reversible hydraulic gear pump. 1.6L (98 cu.in) / min. For cylinder displacement of 160-550 cc (9.8 - 33.5 cu.in). O-Ring Boss (ORB) connections. Includes 3 x ORB-5 to 9/16 UNF fittings. SteadySteer compatible. (NAC-3 / AC42 required).