The QSC SP-16X is a loudspeaker extension pole. This black-painted, metal pole is 16-inch (406 mm) long with a 35 mm diameter and features a male M20 thread on one end and a female M20 thread on the other. The installation of the SP-16X extension pole on its own is straightforward as the pole end with the male M20 thread is screwed into the available QSC KS Series M20 female-threaded socket. The main loudspeaker is fitted on the top of the pole by inserting the upper pole-end into the available pole socket on the bottom of the loudspeaker. Used as an extension pole, one needs to first screw the SP-16X in the subwoofer's M20 female-threaded socket. Once securely assembled, the second loudspeaker pole (SP-26 or SP-36) can be mounted on top of the SP-16X via the male/female M20 threads. Consult the QSC KS Series User Manual to determine which poles - and pole combinations - are safe to use with the various QSC main loudspeaker Series.