Máy đo tốc độ vòng quay Contact & Non-contact Handheld Tachometer with an LCD (Acquest SKS Coporation) Nidec Shimpo DT-207LR

Capable of both contact and non-contact measurement with a single unit
 

Capable of a wide range of unit conversion and indication
Contact: rpm, ypm, fpm, mpm, ipm, m, yrd, FT, IN
Non-contact: rpm

Capable of storing maximum, minimum, and last-measured values plus 10 other measurements, which can be retained for 5 minutes

Lightweight and durable housing made of die-cast aluminum

Energy-saving and eco-friendly design
It can perform measurement for 25 consecutive hours with two AA alkaline batteries.