Choose from a traditional metal sharpener; a plastic cased pastel pencil version, specially designed for sharpening the more delicate pastel strip; or the two hole sharpener which has a large visible reservoir for shavings and is capable of sharpening 7 and 8mm diameter pencils.
Remember to keep the pencil and sharpener in a straight line, otherwise the point may break - and don’t expect your sharpener to stay sharp for ever (as many people do!).