This telescoping sensor-wand expands up to 36.25” (92cm), as measured from the end of the handle to the center of the mount. When fully collapsed, the wand measure 11.25." (28.5 cm) It's compataible with all Apogee Instruments sensor-heads including those attached to our PAR-meters. It's compatible for open-air use as well as submerged underwater in both fresh and salt water environments such as reef tanks. Product includes velcro-strips for securing sensor cable to wand as it extends as well as our vinyl screws for afixing sensor head to the wand-mount.