The eyeliner comes in a bottle with a thin brush tip applicator nice and thin, which made it nice and easy to create a crisp clean line, especially for any winged eyeliner looks. The tip is also quite flexible, but I still found it really easy to use.
The formula is very pigmented and black, and not too runny. It dries to a slightly shiny/satin finish, and lasted on the eyelid really well for me. Sometimes I get watery eyes and the eyeliner did not budge at all. I can't vouch that it will stay on for 36 hours, but it did last all day for me (~12 hours) and came off nice and easily with my waterproof eye makeup remover.
This liner does do what it says it will do however it’s just not for me. I didn’t like the applicator as I prefer a felt tip applicator. My eyes were itchy after I put this liner on so sadly I don’t think it agrees with my skin.