works great short term [SEP] this is great for whitening for a specific occasion my teeth were super white looked great in photos received lots of compliments it does not last longterm though so i would not use it for permanent whitening or maintenance i have permanent retainers on my teeth so it is difficult to get strips to stick this was easy to use with permanent retainers and you can pop in the goo tray and watch tv or whatever i did like the hands free part but it does get annoying to have to rinse and reapply the gel every minutes i would use again in a pinch but would prefer professional whitening longterm though it is the pricier option