Albeit expensive, the real BeautyBlender is amazing!!!! Used damp, it helps to make the foundation look like a second skin and it is great for setting your under-eye concealer or pressing powder into the face.

There are a ton of dupes for this product (which I have not tried) but I always think it's better to go with the real thing. I will get my hands on one of the cheap ones and do a comparison at some stage.