Bosch GLM 15 Compact Laser Measure, 50-Feet (Discontinued by Manufacturer) One button operation - press button once to begin measuring in continuous mode, press same button again to hold measurement Continuous measurement mode - starts measuring as soon as it's turned on Laser precision technology - accuracy to 1/8-Inch Compact size and shape - easily portable and will rest on any flat surface Distance range - measures up to 50-Feet Class IIa laser product, &lt;1mW power output