Hongville Heat Mats Thermostat Controller ensures that your plants’ roots enjoy consistently ideal temperatures by precisely controlling and maintaining the heat output of the mat in accordance with the temperature you select. Instructions: 1. Press the "SET" button to display the current pre-set temperature. 2. Press and hold the "SET" button for three seconds to enter temperature selection mode. 3. Press the "UP" or "DOWN" button to adjust the temperature. 4. Press the "SET" button again to set the chosen temperature. Warning: Do Not Immerse Digital Controller in Water. Disclaimer- The use of Hongville products should be installed professionally and not in enclosed areas. Buyer represents that by purchasing Hongville products, buyer has special knowledge or has consulted a professional on product’s use. In no event will the Company or any of its subsidiaries or their parent companies be liable to you for any direct, special, indirect, consequential, incidental damages or any damages of any kind even if the Company has been advised of the possibility thereof. Package Includes: Seedling Heat Mat Thermostat Controller x 1 PC