I really like my Bodum coffee presses - I have two sizes, and was delighted to see I could replace the beaker separately. But watch out if you order a replacement beaker. My small one holds 3 of what I think are ordinary cups, so I ordered the 3 cup replacement beaker by mistake. Looks like my small one is actually an 8 cup unit, and my big one (which hold 5 of my cups) is a 12 cup unit. There is no info on the Bodum itself of how big it is, so if you don't remember, it takes some guesswork to figure out whether you have a "3", "8", or "12" cup Bodum.
Study the measurements carefully and get the closest match. The oz's held are the easiest way to tell, but of course if the beaker is broken you have a problem.