The Boondockers EFI box is the most controllable box on the market to fine tune your EFI. It allows you to increase or decrease fuel delivery at multiple rpm ranges on your sled. Too lean on top end but rich in the midrange? No problem, the Boondockers box will let you dial in the fuel settings independently. The PTO cylinder running richer than the MAG cylinder? Even them out with the Trim Value setting. Got Nitrous? The box has a seperate input for use with nitrous as well! Whether you have a stocker that needs minor tweaking or a big bore with Nitrous, this box will do the trick. Simply plugs into the electrical system between the ECU and injectors and will not interfere with the ECU operation. The box holds five possible fuel maps for your testing pleasure and the box can easily be mounted on the dash or handlebars. Comes with complete instructions. Currently available for Arctic Cat and Polaris EFI models.