The kit comes with 8 syringes of the whitening gel, so I have plenty for touch-ups, and a little goes a very long way. I love that it includes a brush so that you can brush the gel on your teeth, before using the mouth piece. I'm not sure how much of a difference it makes by using the light, as the light is only used as an accelerator to speed things up.
I can tell you that I highly recommend this product, and that it has done a great job, and has by far, surpassed any other product that I have used. I feel that for the price, this is an excellent deal, as the package has everything included that you would use. I look forward to seeing how white my teeth really can get by using this product. If you follow the instructions that are provided, you won't be disappointed.
If interested in purchasing Dr Song's amazing product to here is the link
I received one or more of the products mentioned above for free using Tomoson.com. Regardless, I only recommend products or services I use personally and believe will be good for my readers.