Rostra 250-1729 Cruise Control Switch for Trailblazer, Silverado, Envoy, Sierra 2002-2004 Safe, reliable performance that increases fuel economy; Reduces vehicle wear-and-tear; Provides relaxed travel at preset speeds Same functionality as OEM systems featuring: Set, Accel, Coast, Resume, and Disengage Set function-locks predetermined speed with the touch of a button. Hodling accel function creates acceleration, speed is maintained once released. Coast Function allows you to reduce/reset cruise speed. System can be disabled 3 ways-tap brakes/depress clutch, switch engine off Electronic servo requires no vacuum; More reliable, no vacuum diaphragm to leak or fail; Easier to install since vacuum connection is not required Consistent operation regardless of altitude or engine size