Precise red LED light source (laser beam) together with a reflective strip, non-contact measurements can be made safely up to 40cm (15 3/4") from the target. For measuring in rpm and rpm. 6 digit clear LCD display with optional back light. Data hold function. Auto power 'OFF' & low power indicator. Battery operated: DC1.5V 3x AAA (included). Conforms with EN61326-6: 2006 and EN61326-2-2: 2006. Pack includes Digital Tachometer. 2x 30cm Reflective Strips. Wrist strap. Hard carry case. DC1.5V x3 AAA batteries (installed). Instruction manual.