Model: CM8856 Application It meets the standards of both ISO2178and ISO 2361 as well as DIN, ASTM and BS. It can be used both in the laboratory and in harsh field conditions. SPECIFICATIONS Display: 4 digits LCD, backlit Range: 0~ 1250 ¼ m/ 0~ 50mil ( other ranges can be specified ) Min.radius workpiece: F: Convex1.5mm/ Concave 25mm N: Convex 3mm/ Concave 50mm Min. measuring area: 6mm Min.Sample thickness : 0.3mm Resolution: 0.1 ¼ m ( 0~ 99.9¼ m) ; 1 ¼ m ( over 100¼ m) Accuracy: ± 1~ 3% n or 2.5 ¼ m or 0.1mil ( Whichever is the greater) Bttery Indicator: Low batter indicator. PC interface: with RS-232C interface Power supply: 2x1.5 AAA( UM-4) battery Operating condition: Temp. 0~ 50 . Humidity