https://etaproducts.gr/en/catalog/category/metrhtes-palmwntemaxiwn-me-prory8mish-hlektronikoi/
Digital tachometers | eta
digital tachometerseta
https://compactinstruments.co.uk/product-category/mechanical-and-digital-handheld-tachometers/
Mechanical & Digital Tachometers - Compact Instruments Ltd
The handheld tachometer is a tool for measuring revolutions within the industrial sector, optically or mechanically, used for maintenance and calibration.
digital tachometersmechanicalcompactinstrumentsltd