Got to personalizing my S4 with the DJ Tech Tools Super Knobs. They feel and look great with the S4, but do get a little pricy. However, if you are into customizing and making your S4 your very own I would definitely recommend getting a few of these. They are definitely more than just looks they are functional as well. Installation on the S4 is a little difficult. Some come off easily while many took some extra effort. If you still can’t manage to wiggle them off I would recommend taping a small thing flathead or knife with some electrical tape or gaffers and pry the knobs off from the bottom. (Note: do this at your own risk. I am not responsible if you scratch or damage your controller) It shouldn’t use too much effort but having the knife or flathead definitely makes things a lot easier, and saves your fingers and thumbs. Good luck!
Check the video below for more info on how they were designed for all of us DJs.