I purchased this to replace the smaller 400x400 size bed that I originally ordered. The small one works, but the larger one is much nicer to work with. The aluminum tray underneath is great for protecting the bench top, and helps catch the tiny pieces that fall through the honeycomb when cutting out holes and tabs in small projects. I highly recommend getting the larger size. It's much easier to set the whole laser on top of the bed and not worry about needing to align the bed.