How it works: In order to extend the liner out of the pencil you tug down on the part of the pencil. Once you extend the liner out, you can't retract it (put it back in the pencil), so it just ends up getting sharpened away inside the cap that you twist on. Inside the tip of the cap is a little conical space (I'm assuming) that shapes the eyeliner to be a perfect point every time you use it.
The eyeliner is good quality. Very pigmented, nice texture. However, I felt like there wasn't a lot of product in the pencil since I used it all up in 3 weeks max. I was really surprised! The liner broke off a few times, wasting a lot of the 1 inch (or 0.01oz) of liner that comes in the pencil. If you have serious issues with eyeliner sharpeners, then I say this product is for you! I would rather buy Smashbox's normal pencil and spend the same amount for 4 times the product (0.04oz).