The Exo Terra digital thermometer is equipped with a remote sensor for accurate measurement and durability. This precision instrument comes with a programmable minimum and maximum memory setting which can be controlled with one single button. The Exo Terra digital thermometer s sensor is held in place with a suction cup while the instrument can be mounted in three ways with velcro (included) with a screw or it simply slides into place on an Exo Terra compact top or dual top. maintaining the proper temperature and humidity levels in a terrarium is vital for the well being and health of all reptiles and amphibians.