The Planet Waves Humidifier Kit includes a Humidity & Temporature Sensor and a Humidpak.

Humidity & Temporature Sensor
The Planet Waves Humidity & Temperature Sensor is a precision-designed hygrometer that digitally indicates accurate relative humidity levels ranging from low (under 20%) to 99%. Temperature is displayed in either Fahrenheit or Centigrade, ranging from -32F to 122F (-35C to 50C). The HTS includes a programmable set point, as well as a memory feature that indicates date/time of the highest & lowest temperature/humidity levels the instrument has been exposed to. Get one for each of your instruments. It' a wise investment to properly install and use a Planet Waves HTS and a humidifier in each of your instrument cases.

Humidpak
The Planet Waves Humidipak is the only maintenance free, two-way humidity control system for guitar. It automatically maintains the optimal 45-50% relative humidity level within your instrument case, eliminating the guesswork and potential mess related to refilling a humidifier. Unlike refillable humidifiers, the Humidipak system provides true œtwo-way purified humidity control by adding and removing moisture on demand. No more manual adjustments based on seasonal changes, geographic locations, temperature, or other factors. The Humidipak Kit comes with 3 Humidipaks and a soft mesh pouch that will not harm your instrument's finish. Humidipaks last between two and six months and should always be kept in a sealed environment like a hardshell case. Once the Humidipaks become firm, discard and replace using the 3 refills that come in the Planet Waves Humidipak Replacement Pack (PW-HPRP-03). This all new, reformulated, patented ldquo; two-way rdquo; humidification system maintains 45-50% relative humidity which eliminates all maintenance and guesswork. this system is recommended by taylor guitars and others for maintaining the stability and playability of your instrument.