This product is sold directly from Hubitools.
Use the promo code Diagnosedan20 to claim your 20% discount at the payment page.

Measures RPM from 1 to 99999
Kit includes reflective tape to affix to the rotating element to measure
Wide measuring range and high resolution
Yellow green backlight makes sure that tachometer can work normally in any light circumstance
Memory call feature
Can be connected 6V direct current stable voltage power in favor of using for long time
Low battery voltage indication