The GHP Reactor unit itself is genuinely compact (6.7"W x 2.0"H x 3.5"D) and, like the rest of the Reactor line, uses a solid-state 9-axis AHRS so it can be mounted virtually anywhere on the boat regardless of orientation, plus Garmin's Shadow Drive technology, which lets the captain take manual control of the helm at any time and automatically re-engages the autopilot once a steady course is resumed. This 1-litre-pump version is sized for smaller boats than the 1.2L pump variant sold alongside it. As a genuine start pack, this is a complete, ready-to-install autopilot solution out of the box, controllable via a compatible Garmin chartplotter, GHC instrument or smart device, and Garmin backs it with a two-year warranty. This start pack is Garmin's recommended entry point for a first-time hydraulic autopilot installation, since every core component ships together in one box rather than needing separate parts sourced.