In the market for a mattebox for your shooting rig? Well which size do you want…4×4, or maybe 4×5.65? Perhaps the mack-daddy 6.6×6.6? Or one that accepts circular filters instead…

As you can see, there are a number of sizes and styles available from a variety of manufacturers. If you aren’t sure, here’s a great resource that will explain why you might need a certain size matte-box for your application over another. And many thanks to the always-informative Bruce Allen for the link!