Plastic pH electrode (probe) storage bottles with rubber compression fitting and screw cap, suitable for use with pH electrodes with a 12mm stem diameter (only). Using these simple bottles helps to protect and prolong the life of electrodes. To use, simply add 1ml of storage solution (PHM-500-150) to the bottle, carefully push the tip of the electrode/probe through the cap into the bottle, then tighten the cap. Electrodes should be cleaned first by rinsing with water or cleaning solution (PHM-500-100), before gently dabbing with soft tissue to remove excess liquid. When required for use again, the electrode bottle cap should be unscrewed, before removing and rinsing the electrode. Supplied as a pack of 5.