A longeing cavesson is a piece of equipment used when longeing

Longeing

Longeing or lungeing is a technique for training horses, where a horse is asked to work at the end of a long line and respond to commands from a handler on the ground who holds the line. It is also a critical component of the sport of equestrian vaulting...

 a horse. A longeing cavesson consists of a heavy, padded noseband

Noseband

A noseband is the part of a horse's bridle that encircles the nose and jaw of the horse. In English riding, where the noseband is separately attached to its own headstall or crownpiece, held independently of the bit, it is often called a cavesson or caveson noseband...

, metal rings to attach the longe line, a throatlatch, and sometimes additional straps such as a jowl strap or a browband for added stability. It is placed on the horse's head in a manner somewhat akin to a halter

Halter

A halter, headcollar, or, less often, headstall, is headgear that is used to lead or tie up livestock and, occasionally, other animals; it fits behind the ears , and around the muzzle. To handle the animal, usually a lead rope or lead shank is attached...

, but provides significantly more control than a halter, without placing pressure on the horse's mouth as a bridle would. The noseband should be just below the cheekbone, several inches above the nostrils sitting on the nasal bone, and fitted snugly. The jowl strap should be very snug to prevent the cavesson from slipping into the horse's eye.

The key feature of a longeing cavesson is the strategic placement of rings for varying places to attach the longe line: one at the top of the nasal bone and one each side of the noseband. Many other types of headgear may be used for longeing, but the longeing cavesson is most commonly associated with dressage

Dressage

Dressage is a competitive equestrian sport, defined by the International Equestrian Federation as "the highest expression of horse training." Competitions are held at all levels from amateur to the World Equestrian Games...

 and related training methods and is designed to allow more subtle communication between handler and horse.

A longeing cavesson may be used with a snaffle

Snaffle

A snaffle bit is the most common type of bit used while riding horses. It consists of a bit mouthpiece with a ring on either side and acts with direct pressure. A bridle utilizing only a snaffle bit is often called a "snaffle bridle," particularly in the English riding disciplines...

 bridle. The cavesson is put on under the bridle, with the noseband of the cavesson under the bridle cheekpieces. On some horses, the bridle cheekpieces may need to be lengthened to allow this. If the bridle also has its own cavesson

Noseband

A noseband is the part of a horse's bridle that encircles the nose and jaw of the horse. In English riding, where the noseband is separately attached to its own headstall or crownpiece, held independently of the bit, it is often called a cavesson or caveson noseband...

, it may need to be removed to reduce bulk and avoid interference with other components.