The Giottos CL1310 Retracting 2 Position Goats Hair Brush is an excellent addition to anyone's gear bag. This brush, 3.5 x .5 x 1", fits neatly in any pocket and can be a lifesaver for getting dirt and other light contaminants off your optics.
I like the size and softness. It definitely fits the bill.
I purchased one of these brushes about 4 years ago and like it quite a bit. Recently, I decided to buy a spare. After getting over the nearly 64% price increase, I was disappointed to see the quality aluminum case is now the cheap plastic. As such it no longer matches the picture, which should be changed to reflect the product being sold. The brush itself seems ok, but I wouldn't trust Giottos to not cut corners there as well.
