Hayes 81775 Sway Master Electronic Sway Control

Eliminates sway when weight distribution is not needed. It provides simultaneous braking when sway is detected to all trailer brakes on 1 to 4 axle trailers. Plug and play design and utilizes your factory 7-way connections. No set-up required, self calibrating. No hardwiring. The unit activates appropriate amount of braking based upon trailer speed and amount of sway.