The Kyser + Classics Dr. Stringfellow Fret Board Conditioner is a polish for your electric and acoustic guitar. The one that I have and that I've used is the lemon oil version, as I believe that there are a few different ones to choose from, although I don't know the difference if there are any major ones. The polish comes in a small spray can, and it only takes a couple of squirts to do the job. The directions say that you should put it on a rag and let it sit for 20 minutes for the best results. I love the way that my neck feels after I apply it, as it comes off a lot smoother after. I've had the Kyser + Classics Dr. Stringfellow Fret Board Conditioner for about five or six years and still have a good amount left! While I should say that it isn't something that I use all that often, it is still worth noting the longevity of it, so if you have a bottle of this expect to have it for a while unless you're using it all the time. I use the Kyser + Classics Dr. Stringfellow Fret Board Conditioner on both my Martin acoustic guitar's neck and my Fender Strat and Jazzmaster. While it isn't a polish that is essential for anyone, I like having it around as it comes in handy when my necks need a clean and polish. The price of Kyser + Classics Dr. Stringfellow Fret Board Conditioner isn't very expensive at all, and like I said it is something that will last you for a long time. I'm not sure what else to say about this as it is something that you either need and want or you feel that you don't have a need for it. It's really just a matter of personal preference, but I'm glad that I have mine around...