A CRT monitor that's called a 17-inch model has a viewable area measuring roughly 16 inches diagonally. A 17-inch model weighs about 40 pounds and is about 18 inches deep. It demands a big, sturdy desk and some muscle to move it around. When figuring out how much monitor will fit in your work area, keep in mind that you'll need space for cabling, ventilation, tilting the screen to get a good view, and, in some cases, side-mounted loudspeakers. If you plan to use your current desk, make sure there's room for a larger monitor.
Power is another consideration.
Most new models have an Energy Star low-power mode that uses under 8 watts when the computer is idle. But size isn't everything. There are two basic types of CRTs. The image characteristics vary somewhat, so it's a good idea to view both to see which type you prefer. Some newer CRTs have flattened, squared-off screens that reduce glare.