This telescopic wand contains a mounting fixture with two mounting holes to accommodate both Apogee Instruments' narrower and wider diameter sensors. The wand is extendable from 8.5 to 33 inches (84 cm), allowing the user to measure photons of light in hard-to-reach places, such as over plant canopies and in corners of growth chambers, using Apogee sensors. For taking measurements in freshwater or saltwater, we recommend our AM-320 water-submersible sensor wand to avoid corrosion. If you are looking to purchase both an Apogee meter and a wand at a discounted cost, check out our meter bundles for the MQ-500 and MQ-610.