The Oakton ORP 50 WD-35634-45 Waterproof Testr features a replaceable double-junction platinum electrode — ideal for checking dirty water, heavy metals, sulfides, and organics. Valox®electrode body resists most chemicals. Use this versatile instrument for applications ranging from swimming pool testing to pulp bleaching. Meter features 2mV accuracy and a +/-150mV offset. Redesigned leakproof cap functions as a sample cup, hydrating cup, and as a stabilizing base to stand meter upright. Housing allows you to attach a lanyard (included) for easy retrieval.