Reeds come in standard sizes to fit specific looms, but that doesn't mean that you can't use a Leclerc reed in a Schacht loom, for example. The key is to know the measurements that you need. If the top of your beater is adjustable, you have more flexibility on height. You can use a reed that is narrower than your maximum weaving width but you can't always go wider than the weaving width, as some beaters have closed ends which limit the total width of the reed that can be fitted in the beater. If you aren't sure which reed to buy or need a size that we don't carry, call us at 800-468-0035 or email us!