The female swivel stem allows the fixture connections to be made, mounted onto a 1/2" NPS female fitting, aimed, and then fixed in place with the adjustment locking screw located near the base of the stem.
Once the fixture is mounted, by loosening the fixture's adjustment locking screw with provided allen wrench, the fixture can be aimed, on the vertical axis, and then fixed in place by once again, tightening the adjustment locking screw.
The main stem adjustment locking screw allows for y-axis aiming up to fully vertical positions. The female swivel stem (FSS) allows for almost 360° rotational aiming with an adjustment locking screw to keep the fixture in the desired position. With these two features, virtually any aiming position can be achieved.