The adjuster connects frontlines and chicken loop. By adjusting the adjuster the kitesurfer changes the length ratio of front- and backlines. This changes the angle of attack to the wind and thus the power (pull) of the kite.
For most kite manufacturers the adjuster is the center of the depower system and is therefore an important safety feature.
Unfortunately the manufacturers do not have a uniform adjuster technology, so you should familiarize yourself with the adjuster before your first ride.
By changing the adjuster setting, the length ratio of frontlines to backlines is changed, so the kite can be adjusted to the wind conditions and the wishes of the kiter.
You can use the adjuster to trim the kite so that the position of the bar does not change with changing wind conditions, so that the kiter always has the same attitude.
By pulling the kite adjuster, the frontlines become shorter, making the kite's angle of attack less effective (=depower).
Pulling the adjuster corresponds to pushing the bar away on the depower line.
When opening or releasing the adjuster the frontlines get longer, so the angle of attack of the kite becomes more effective (=Power).
Opening the adjuster is the same as pulling the bar on the depower line.
The adjuster is either above the depower light or below the bar on the chicken loop.
You can distinguish between a webbing adjuster, which works on the pull-pull principle, and a clampcleat adjuster.