You can purchase these in different variety packs for $5.50 (tax & shipping included) from http://www.thebrushguard.com/. I purchased mine from Coastal Scents for $4.95 (+ shipping).
View the reviews for the brush guard on makeupalley here.
Review: The basic concept of this product is to keep the bristles of the brush together while drying.. and to dry the brushes upside down so excess water won't seep into the wooden handle and cause the handle to separate from the brush in the future. I didn't really buy into the whole idea of the brush guard (considering these have been around for a while).. Although it's a good concept and it makes a lot of sense, I never really found the urge to purchase them. But while I was making a purchase on Coastal Scents, before checkout I was tossing in some last minute things and I figured I'd give them a try. I couldn't think of any other method or tool to use to dry my brushes facing down. When I clean my brushes, I usually lay them flat to dry and by the following morning, they are usually dry and fluffy. No problems. No serious issues with my brush bristles fraying or straying away.. and haven't had any brushes separate from the handle (well, high end at least). When I used the brush guards, it dried my brushes just as good & it kept all of the bristles together. I find the drying time to be very long (for this post, I had them drying for 10 hours and they were still damp. I had no choice but to use them by that point, so I couldn't take a picture of them dry). You really need 24 hours for them to dry completely. I find that my goat hair/natural bristle brushes dried in a much shorter time (it's always the case anyway) than the synthetic brushes. I do think this will help maintain my brushes well and that it will give my brushes a longer life span. Overall, I think it's a good product. Nothing I'd continuously rave about.. but, worth the $5.
Do you own these or anything similar? What are your thoughts?