This is a solid block of carnauba wax, popular with woodturners. It gives a bright gloss finish and is also very hard wearing, able to withstand a medium amount of handling without showing finger marks.
Apply over a sanding sealer by holding it against your work at it revolves on the lathe. Do not press too much – the wax is very hard and can scratch softer woods – the idea is to generate enough heat for the wax to melt slightly and transfer onto the wood. (This is easier than it sounds!). Use sparingly, and use the polishing process (using Safety Cloth) to ensure the wax is spread evenly. Buffing will produce a high gloss finish.