TACHOMETER LASER PHOTO TACHOMETER * Long detecting distance for photo Tach. up to 2 meters. * Photo Tach. : 10 to 99, 999 RPM * Accuracy : ( 0.05 % + 1 d) . * Size: 190 x 73 x 37 mm. Specifications Display     5 digits, 10mm ( 0.4 " ) LCD, with function annunciation Measurement     10 to 99, 999 RPM Memory     Memorize last/ Max./ Min. value Data output     RS232 PC serial interface Operating temperature     0 to 50  ( 32° F to 122° F )  Operating Humidity     Less than 80% R.H. Power Consumption     Photo Tachometer: Approx. DC 29mA Contact Tachometer: Approx DC 5mA Weight     187g ( 0.41 LB)  Dimension     156 x 50 x 33mm ( 6.1 x 2.0 x 1.3 inch)  Resolution     RPM: 0.1 RPM ( < 1, 000 RPM) , 1RPM ( e 1, 000 RPM)  Accuracy     ± ( 0.05% + 1 digit)  * Spec. of detecting distance are that under the size of reflecting tape is 10mm square & the measuring RPM value is 1, 800 RPM. The max. & min. detecting distance may change under different environment, different reflecting tape or the measuring RPM beyond 1800 RP