It is used under the following accasions:A, in the case of strong sunlight or target reflection is not good, please use the reflectorB, reflecting plate has good reflection effect and measurement on the table or floor, or as a baffle. C, it can be used in rough uneven walls and astigmatism surface (glass lens stainless steel), the reflected signal is not good or interfere with the strengthening of local signal reflection Instant measurement of distance, area & volume with one button operation: YESSelf Calibration: YESWide measuring range: YESHigh accuracy: ±2mm (0.079inch)Automatic calculation of Area and Volume: YESIndirect measurement by Pythagorean Theorem: YESSingle/Continous measurement: YESMax/Min distance tracking (display value): YESEasy Addition/ Subtraction of measurement: YESSet up front / middle / rear benchmark: YESSelectable meter(m), inch(in) and feet(ft): YESData store/ recall function: YESData Hold / Data clear function: 100 unitsAir Bubble Level: YES, IncludedEasy targeting with bright laser pointer: YESLarge LCD with backlight and multi-line display (4 lines): YESAuto correction and error report technology: YESBuzzer indication: YESBattery status Indication: YESIP54 protection (dust & splash proof): YESAuto / Manual power off function: YESMultifunction with intelligent calculation: YESCompact & handy design: YESCE, ROHS, FCC certificate: YESSpecification: Package Weight One Package Weight 0.19kgs / 0.42lb One Package Size 15.9cm * 8.7cm * 4.8cm / 6.26inch * 3.43inch * 1.89inch Qty per Carton 79 Carton Weight 15.00kgs / 33.07lb Carton Size 68cm * 37cm * 20cm / 26.77inch * 14.57inch * 7.87inch Loading Container 20GP: 529 cartons * 79 pcs = 41791 pcs 40HQ: 1230 cartons * 79 pcs = 97170 pcs