Mengshen Digital Tachometer, 2 in 1 Non-Contact & Contact Tach Rotation Speed Measurement RPM Meter M522

Thanks for coming, you deserve the best! This is Mengshen's Handheld Professional Digital Tachometer M522. Specifications: Contact Measurement Range: 2~ 20,000 RPM Non-contact Measurement Range: 2~ 99,999 RPM Resolution Ratio: 0.1 or 1 Accuracy: +/-(0.02%) + 2 digit REV Measuring Range: 1-99999 Sampling Time: 0.5sec Measurement Distance: 50mm ~ 600mm Display: 5-digit Backlight LCD Display Working Temperature: 0°C-50°C(32°F-122°F) Power Consumption: 45mA Power Supply:9V DC Battery(Included) Please Attention Before using, you can practice or test it on conduction motors. Usually keep device close to the object measured to reduce the size of the laser dot can get a more accurate readings. The purpose of the reflective tape is to offer a good contrast between background and measuring area, but if the part measured has other reflective surfaces, like shiny metal, please apply a non-reflective tape(black or a dark color tape) to act as background. If reflective tape ran out, white pain