I have one bad experience with them, last december I bought a heater since its very cold then.. after a few days my heater was overheated and sparks and also it burn the extension cord... lucky for me we were all awake that time and we notice it early if not we were all burn by fire... I ask if they can exchange it for new one and they refuse they say it should not be use overnight...whew I was shock since it is written at the label that 12hrs guaranteed.. and the fact that I only use it for less than 7hrs... I dot insist since I know I will not prevail... 

donaldduck168