Extend the life of your pH or ORP/REDOX Probes. Probe tips dry out very quickly which can cause inaccurate readings. Probes tips need to be kept hydrated by placing them in a storage solution in a properly sealed bottle. The PINPOINT Deluxe Storage Bottle will provide the protection your probes need. Bottle dimensions: 2½” high x 1” in diameter. The input hole is ½” or 13mm and can be tightened additionally to make the proper snug connection. To use the storage bottle, slightly unscrew the cap, insert the electrode midway into the bottle containing storage solution, and gently screw on cap. American Marine Probe Storage Solution (also available on Amazon) is the perfect fluid for the storage of any pH or ORP/REDOX electrode. If you have any questions please contact us. Satisfaction Guaranteed.