I love fibre brushes because every since I discovered applying foundation with them makes it so much easier, i've started searching for a bunch of them. I love them for all purposes really. You can find this brush at Target, you know those studio tool brushes that are usually near the beauty tools section. I have yet to get one myself, I saw it but then I didn't know how it would work, but then I saw the review on makeupalley and now i've gotta go! It's $6 which is cheaper than the sonia kashuk one!
*this photo is not mine but i wanted to post this because i love duo fibre brushes!