This product really helped the longevity of my lipstick and prevented feathering. It's great for any colour lipstick as it is pretty much clear and isn't drying at all.
My only issue is that its a little bit flimsy as a retractable lip liner, mine broke when I accidentally dropped even when it was closed.
This is the perfect lip liner for those who don't 'like' to wear noticeable lip liner (like me most of the time), who have a vast coloured lipstick collection and who want to help their lippy stay within the lip lines. I picked up 2 of these in a buy 1 get one free sale & it's one of the best purchases I have ever made. Because there is no colour to the liner you can wear it with every colour of lipstick or gloss imaginable. In particular I like to wear it under my liquid lipsticks like the Milani intense colour where the formula has a tendency to 'bleed'. This also works as a primer for the lips.
Tips: You need this is your makeup collection!