Dissolved Oxygen DO Replaceable Probe for DO Meter YSI 550A | YSI 559

Dissolved Oxygen DO Replaceable Probe for DO Meter YSI 550A amp; 556 | YSI 559 Descriptions : Dissolved Oxygen DO Replaceable Probe for DO Meter YSI 550A amp; 556 | YSI 559 Easy user-replaceable sensor allows for quick sensor replacements, if needed. Quickly switch DO sensors without having to send in the instrument for repair or replacing the entire cable assembly. Uses convenient screw-on cap membranes making membrane changes simple and easy.