Reply to Source for Knobs oriented in the "opposite direction"

Anyone know of a source to buy knobs that are oriented "opposite" to the DJTT Chroma Caps? I have some gear (mixers etc.) that the knobs can fit, but the indicator position is wrong.

For that matter, how do you even identify the orientation when ordering from a store? I'm guessing there are different names/configuration options, but I have no idea what to look for.