The Beyerdynamic NR. 215 5/8" A-3/8"I 1/2" Mic Thread Reducer is an adapter for 5/8" outer and 3/8" (1/2") inner microphone threads. The thread size of microphone clips and stands will often vary. This adaptor will enable you to connect microphone equipment with the European standard of 3/8" prongs to 5/8" thread sockets.