A side pull is a simple bitless bridle. Reins are attached to rings on either side of the horse’s muzzle. When both reins are pulled, pressure is placed on the horse’s nose, asking for a halt. Pulling on one rein cues the horse to turn its head in that direction – pulling on the left rein cues the horse to turn left, and the right rein cues a right turn. The simplest side pulls look and feel like a halter.
Here an improved design by Diana Thompson