This is a set of 3 great little hair rats with flat clips. They are about 2 inches long, 1/2 inch high and completely wrapped in faux hair.
The round top is covered like a small curler would be, wound around. There's also a short little "skirt" of woven hair around the edges, which keeps the wound hair very secure on the rat and covers the ends so that nothing but hair is visible from any angle when in place.
You use these to create volume under your natural hair. I've seen the "bumps" or "bumpits" things, but always feared that a brisk wind would reveal a lump of plastic on my head - not acceptable! These poufs, however, are awesome. Even if your hair slips or a bit shows through, it won't look like you've got something odd in there...its just hair!
The clip is basically a flat wig clip with extra-long teeth. It is very low profile and secure. I got a set of 3 for $9.99 at Ulta, and I'll definitely be picking up another set. The card has great instructions for use - its actually very easy. Tease a little to give the clip something to grab onto without slipping, put them in and smooth out your own hair over the top. I've never been able to make great volume so easily! I tried this on my slept-on hair, and it looked "done" instantly. You can use them with your hair down, with a scarf or headband, or for volume with a pontytail or bun style - they're practically invisible.
All in all, this is a great product that will be a staple for me from now on, and I've tried just about everything. I've done heavy teasing (time-consuming, damaging and falling flat by day's end), used volumizing extensions (expensive and lacking in dramatic lift), and pull-through wiglets (expensive, difficult to match to hair, time-consuming to put on correctly). These little "caterpillars" are the perfect answer. The result looked like a professional blowout, and they never budge in my fine hair. Great product!