f you have two turn signal filaments on each side of your vehicle, you can add these cool sequencers and really indicate your intentions.The STS-2S Sequencer Modules are specially designed to work on cars with separate two-filament turn signal fixtures. Will operate on front OR rear lamps.These modules feature sophisticated electronics that automatically adjust the sequencing speed to match the turn signal flasher in your car. While other products offer you fixed timing or complicated manual adjustments, our modules sense your car's flasher speed and adjust the sequence timing for you. Want more separation between individual lamps? Just put in a slower flasher!Each kit contains two self-adjusting sequencer modules (one for each side of the car), connectors, cable ties, etc. All necessary parts are included -- there is nothing else to buy! Installation takes about an hour, and for most cars, only basic hand tools are required.