F-ONE gives wood its life back. F-ONE is formulated using a complex mixture of the finest ultra refined tree and seed oils to clean, condition & protect your fretboard/fingerboard. 100% free of any lemon oil extracts, waxes, petroleum distillates, silicone, and water. We chose not to use any lemon oil because it contains d-limonene, which is a strong solvent that is used to remove paint and glue. In addition, we believe the high acidity levels of lemon oil can dry out the fretboard over time and require more frequent fretboard care. F-ONE leaves your fretboard looking new, playing great and feeling smooth, never sticky or tacky. Our revolutionary formula penetrates & conditions the wood to dry fast and give it a new look for months. We use 100% naturally produced oils and is safe on all unfinished rosewood, ebony and maple fretboards. F-ONE oil is preferred by some of the most respected repair shops in the world. This large size bottle size is for heavy users such as techs and repair shops.