I saw this product in Mac and I was very intrigued by its claims. It is a mascara undercoat which works as a primer to make your mascara lost longer while conditioning, smoothing and lengthening your lashes. It goes on white and dries as a semi-clear base. I did notice that my lashes felt more conditioned when using this product and the fibers in the formula grab on to your lashes making them appear longer. Although the only problem I has with this was the fact that you had to work quickly with applying your mascara afterward or else the base will dry and it will be impossible to apply mascara and your will be left with clumpy black and white lashes (trust me, it is not a good look). This is a good product and it is a very reasonable $15. However I don’t find myself using this as much as I should. In the morning rush this extra step slips my mind. But it is a good product and I will definitely use it up. I recommend this to people with dry and brittle lashes.