They are huge - each one weighing about 12.75 ounces! I would have personally proportioned the dividers to make smaller bars, but there is a certain 'cool' factor with them being the blocky-size they are. Plus, given the high solubility of salt bars, I won't have to replace them as frequently!
LisaAnne - I bought the mold and inserts shortly after Christmas specifically for salt bars and used it for the first time yesterday. I just got done making another, identical batch (90% CO, 10% castor, 50% salt, 2 grams tussah silk, SF 20%) so I've only used it twice so far. With that being said, I love it! It is a very high quality item that is superbly crafted, and I would expect it to last many, many years.