Trans® Professional Portable D.O. Meter, “HD3030”, 0.00~19.99/0.01ppm, 0~50.0℃, 99 Data MemoryWith 3m Probe, Simultaneous Dual D.O. & Temp. Display, One Touch Calibration, 휴대용 용존 산소 미터 (DH20030300P2140)