This is a
diagram of a typical swivel ring on a delta stunt kite, many manufacturers have chosen to
use a tow point loop instead of a swivel ring but the idea is the same.
The bridle lines run to the attachment points on
the kite. Note that one of the lines is able to slide through the swivel ring. By sliding
the long (main line) through the ring you are raising or lowering the bridle setting. This
is very important to the way the kite flies (or doesn't fly).