If you’re looking for a worthy upgrade to the stock plastic knobs this one is awesome. It's made out of dark steel with a knurled grip and looks fantastic next to the black hardware. The pictures show it on the FT-5 model, but they are compatible with any enclosure.
Be sure to order the number of knobs for the kit you're buying. For example, the FT-5 has 4 knobs and the CR-10 uses 3.