D485(D480) Multi-function hand-held differential pressure meter

● Lowest range 0-100Pa (0.4in. W.c.) ● Measure positive pressure, Negative and differential pressure ● Durable aluminum alloy case in black ● Easy-to-read 0.4 large LCD display ● Switchable backlight for anywhere reading ● Instant choice of English/metric units ● One 9V battery for 100 hours operation ● Range calibration possibly