vivosun durable waterproof seedling heat mat warm hydroponic heating pad 10" x 20.75" met standard vivosun <b>notes:</b><br> -for use indoors only.<br> -for extra effectiveness (and especially in cold environments) add a towel or other insulating fabric under the mat to ensure all the heat is directed upwards. <br> -a humidity dome is recommended to more accurately control moisture levels for seedlings.<br> -a thermometer controller is recommended for more precise temperature regulation.<br> <b>specs:</b><br> -materials: pvc, alloy nikrothal wire and pet film<br> -electrical specs: 18 watts, 120 volts<br> <b>package contains: </b><br>-1 x heating mat<br>-1 x storage bag