Digital monitoring devices have largely replaced the old analog dial gauges, and for good reason: gargoyle gecko care depends on holding fairly precise conditions, and cheap analog hygrometers are notoriously inaccurate. A quality digital combination thermometer-hygrometer with a remote probe lets the keeper read conditions at the exact spot the gecko occupies rather than just at the enclosure wall.
The more advanced devices add data logging and alerts. Units that record temperature and humidity over time reveal patterns a single glance would miss, such as a nightly humidity crash or a midday heat spike, and models with smartphone alerts can warn the keeper when conditions drift outside safe ranges while they are away from home.
Placement and calibration determine how useful any monitor is. Sensors should sit where the gecko actually spends time, often partway up the enclosure, and keepers who want true accuracy periodically check their devices against a known reference. A monitor is only as good as its position and its honesty about the numbers.