This is a great tool for allowing the reader to "plough through" passages of the Hebrew OT quickly. What this book does is list every word in the Hebrew OT that occurs less than 50 times along with a simple definition. The book is arranged by verse order, just like the Hebrew OT, so finding verses is not a problem. The only caveat I offer on this recommendation is that this book is utterly useless to individuals who have NOT kept up with their Hebrew vocabulary memorization. In other words, if you do not know all the words that occur MORE than 50 times, you'll wind up consulting a lexicon no matter what, so picking up a standard lexicon would probably be more cost-effective for you than buying a lexicon AND this book. If you are an intermediate to advanced reader of BH, who has kept up on vocabulary memorization, this is a valuable tool. By the way, one has to memorize the top 600+ frequently ocurring words in BH in order for this book to fill in the gaps.
I am not giving a perfect score because they tend to choose some hard words, but not all of the hard words in the BH. I highly recommend this book to all people who like to translate Hebrew (or need to do so for school) but do not have a lot of time to search B. D. & B's Hebrew Lexicon. Worth every penny for the time that you will save.