The product write-up on Sephora states that this is "A crease-proof, waterproof shadow pencil" and that the "24/7 shadow pencil allows you to blend shimmer, cream, and sparkle finishes. Skip the traditional powder shadow, brushes, and water".
I can attest that this the eyeshadow pencil lives up to these claims. I use it mostly for highlighting the inner corners of my eyes and it lasts all day. I used it as a base today and I am pretty impressed with how nicely it blends in just by using my fingers -which makes this a really convenient little product to have handy:)
As well, I was impressed how long it wears as an all-over shadow: no creasing and the colour stays vibrant.
I also use a similar product from NYX, which is comparable in terms of blendability but the Urban Decay shadow/liner-pencil definitely wears longer. I just wish that it was the price of the NYX one!