Since 1957, AutoMeter has set the standard in performance, accuracy and durability with their legendary Tachometers. The absolute pinnacle of engineering and technology, it's no wonder AutoMeter can lay claim to more motorsports victories than every other gauge manufacturer combined. This model is designed for the specific needs of competition diesel use, featuring a unique sensor engineered to be mounted near the crank pulley which creates a signal from 4 machined grooves or 4 raised bolt heads to precisely monitor engine speed. The patented air core meter movement, wound in house to exacting standards, can move the needle from 0 - 6,000 rpm in just 333 milliseconds ensuring that you never have to worry that your engine is spinning faster than the tach and includes a built-in memory recall to allow review of the highest RPM achieved on your last pass or hook. Built for a lifetime of service under the harshest conditions, this is the no compromise tach for no compromise builds. When you're ready for the best, there isn't another choice. This product ships in approximately 1 days