These combs are great. I've used the flat part to completely srtip wax off the board (once melted in the sun) - the edging tools works well for the rails and the comb does what you expect and freshens up old wax. They've lasted 12 months without any problems.
These are cheap, cheerful, colourful and do the job. There's not much else to say about them really. They have a smoothing side and a roughing side. They have an ergonomic hole to help you attach it to things and are not expensive.