The product in the image is a DT-2236C digital tachometer. This device is a 2-in-1 tool that can measure rotational speed and surface speed using both contact and non-contact methods.
Measuring Range: The non-contact (photo) tachometer measures 2.5 to 99,999 RPM, while the contact tachometer measures 0.5 to 19,999 RPM.
Accuracy: It has an accuracy of ±(0.05% + 1 digit).
Features: The device includes a 5-digit LCD display and memory functions to store maximum, minimum, and last values.