does not work for long [SEP] i used the glo system for a week and it worked great i was very satisfied i received the product in april it is now july and i bought a set of teeth whiteners to refresh my teeth the machine does not work very well now it may work for one or two times but not the whole four times i charge it until it is completely charged and it maybe lasts for a couple times instead of the entire four sessions i am wasting the product because i put it on for the next treatment and the machine dies the whiteness did not last so long either it is not hard to use and it worked when i first received it but it is a lot of money to have it work only for a week