This module allows you to recalibrate OEM electronic speedometers when changing tire size, pulley, or final gearing Easy installation - simply plugs in between the pickup sensor and the stock wiring harness Allows small step corrections of less than 1 mph Correction range of 50% to 200% No power required to maintain calibration when the bike is parked Two sealed buttons allow easy resetting of the speedometer reading while the bike is in motion A must for custom builders using electronic speedometers. MODULE SPEEDO RECALIBRATN