The Fingertip Design European Designer Serdi Cupboard Knob Polished Chrome has a unique appearance - the face is flat with a ripple-like effect. Knob Finish This knob has a modern polished chrome finish and is simple to fit and maintain. Dirt deposits can be easily removed by buffing with a dry, soft cloth. Fingertip Design European Designer Collection The Fingertip Design European Designer Collection from Carlisle Brass features a range of Cebi products. Cebi have been manufacturing cabinet fittings since 1979 and are highly design oriented.