Creates hydraulic pressure to lower and raise the trim tabs using 2 solenoid valves that lock tightly to secure the tabs in place. Power to lower and hold even the largest tabs in place. A Lexan cover provides water resistance, and the trCreatesanslucent reservoir allows fluid check at a glance. Uses automatic transmission fluid. Includes pump, solenoid valves, reservoir and cover. 219-H1179 Mounting bracket sold separately.