I got these for my Hofner HCT 500/1 (contemporary)bass to replace factory ones to make my bass look like a German one :) They fit easily (put them on and secure little bolt with screw driver) and stay OK and yes improve the look! It took some effort to pull of factory knobs, you have to carefully pull them upwards.
After maybe 4 years top metal cover one one of them got lost, I could find it so I have ordered a new knob. That's the reason I rate this product as good, not very good.