Dakota Digital Universal Tachometer Interface SGI-8 This unit can recalibrate an ignition system tachometer signal. Product not compatible with '86-91 VW Vanagon's and other similar models Designed to allow a factory tachometer to function accurately after performing an engine swap to an engine with a different number of cylinders or tach signal Capable of recalibrating tachometer signals for nearly any engine swap combination Adjustability up to 16x