A channel plate adapter 24 is provided for an open-end spinning arrangement 1 having a spinning rotor 3 which turns at a high number of revolutions inside a rotor housing 2 chargable with an underpressure. The channel plate adapter 24 is made of a plastic material, defines the orifice area of a fiber guide conduit and a center through-bore 26 for a yarn withdrawal nozzle 27, and is adapted to be exchangeably arranged in a receiver 22 of a fiber channel plate 10 for closing the rotor housing during a spinning operation. The channel plate adapter (24) has a unitary one-piece clip-on closure (37) at inlet area of the through-bore (26) for centering and fixing the yarn withdrawal nozzle (27) in place.
