Mentadent Dazzle Bright Teeth Whitening is definitely a great option! The fact that you have to plug this in has both pros and cons. The pro is that you can use it immediately, just about anywhere and don't have to wait for it to charge. The cons, obviously you have to be "plugged in" to use it. The mouthpiece is quite bulky and I feel like 30-40min is a bit excessive (and an oversight on my part as I didn't realize until it arrived), but it does deliver results rather quickly. I used this 3 times (about 3 days apart) and there is a noticeable difference. My teeth are about 2 shades lighter and much brighter than before. Absolutely beats the price tag and inconvenience of a professional visit.Mentadent Dazzle Bright Teeth Whitening Kit - 8X Blue LED Light Beaming Enhancer Tray & 4 Mess Free Whitening Gel Pens for Whiter Teeth & Smile, Helps Remove Stains from Coffee, Smoking, Wines, FoodI did see some whitening out of this kit, but I've seen a similar amount of whitening out of the strips that can be bought at any drugstore for less than a third of the price. This does work but it is a lot of work to get there. And I was hoping that the light tray would be rechargeable but it is not. I had a battery pack around that I bring with me on trips to charge my phone at the airport. I was able to get it to work with that so at least I could walk around. They hype the "no need for batteries" concept, but I'd much rather that it was battery powered or, even better, rechargeable. One plus is that the cord has every connector you could want. It makes it easier to find a place to plug it in.I give it 3.5 stars (rounded to 4) because it does what it says it will. There are easier ways to accomplish tooth whitening.Super easy to use, and even more importantly, no sensitivity! Although I am not floored by the results, this system has brightened them a few shades. My teeth were pretty white to begin with due to quarterly use of whitening strips, but this system is great for maintenance. I am such a wuss and get the worst zingers (ie it takes me a month to get through a week or two of strips), but I have zero discomfort from this product.Also, it was was charged enough right out of the box to use it immediately.The best aspect of this product is the intensity of blue light that the tray emits. I was actually surprised by the strength of the illumination. The product requires connection to a power source. They provide three connected options: USB, Lightning and USB-C. You can connect to a computer port, phone, power bank or power plug. I would prefer the power bank, to permit mobility, and not be tethered to one spot. Although, you could connect to your phone (if you have a compatible port), and have the same mobility, But, you'll drain the battery of the phone.The mouth tray is smartly designed, obviously. It demonstrates excellent manufacture with quality materials. It comes with four whitening pens/brushes. Also, as a bonus they include four packets of whitening strips and a sample of pulling oil. These extras are nice, but there seems to be an item missing. The brief user manual mentions putting the mouth tray "into the case for next use." The 'case' is absent from the product set, although it seems that the packaging was designed for it.The manner of presentation give the product a basic level feel. Personally, I think I'd prefer to have a teeth whitening tray that incorporates a rechargeable battery. This would be much more convenient. Odd enough, competing products with a battery feature are less expensive than this product. And, these battery powered units recommend 10 - 20 minute treatment sessions, as opposed to the 30 - 40 minutes stated in this product's user manual.So, while this is a viable solution for teeth whitening, and matches the pictures and descriptions, there are better options. Based on these considerations, this product earns a 4 - 4.25 star rating.Does this product work? Yes. However I Don t like the fact that you have to sit next to an outlet the whole time. It restricts what you can do while whitening your teeth. I have another led teeth whitening kit that is recgatgeable so you can walk around... Sweep do dishes etc. Its not usb its rechargeable. I also prefer whitening strips vs gel pens for some reason i feel like it adheres to the teeth more. Over all this does work but its not convienient.I had a $450 whitening treatment at the dentist's that was very similar to this product. It didn't work that well on my teeth, as they were maybe a shade lighter afterwards. I got the kit to take home to continue with my treatment. The professional kit had me apply the bleach, use the LED light for 10 minutes, and then repeat the process two more time.This kit by Mentadent only has you apply the bleach once, then whiten for 30-40 minutes. I'm thinking this is to lessen the possibility of tooth sensitivity. (As an aside, if you use a toothpaste for sensitive teeth during treatment, as well as two weeks prior, this can eliminate sensitivity.) As expected, my teeth were only one shade lighter. I'll put this down to my teeth being resistant to whitening, rather than a failure of the product itself. Overall, I think it's worth a try.It is a good product, does about what a dentist can do but takes a bit of time and some effort of keeping up the program. But once done and done properly, does a nice job of whitening teeth.