For KaVo MULTIflex / MULTIflex LUX Coupling. For KAVO Multiflex / Multiflex LUX. 2PQ2-K Handpiece / 3PQ2-K Handpiece. The NON-RETRACTION structure in the handpiece, prevents suction of oral fluids in a patient's mouth into the water line of the handpiece at the spray water outlet port.