A body belt is any waist belt

Belt (clothing)

A belt is a flexible band or strap, typically made of leather or heavy cloth, and worn around the waist. A belt supports trousers or other articles of clothing.-History:...

 which has D-ring

D-ring

A D-ring is an item of hardware, usually a metal ring shaped like the letter D. It may be used at the end of a leather or fabric strap, or may be secured to a surface with a metal or fabric strap...

s or other attachment points. The belts can be used as medical restraints in institutions for bed and wheelchair restraints, and for safety in activities such as abseiling

Abseiling

Abseiling , rappelling in American English, is the controlled descent down a rock face using a rope; climbers use this technique when a cliff or slope is too steep and/or dangerous to descend without protection.- Slang terms :...

 or construction work. When they are used in sexual bondage plays they are commonly referred to as bondage belts, and also worn in fetish clothing. The belts are usually fastened with buckles and some by a locking

Lock (device)

A lock is a mechanical or electronic fastening device that is released by a physical object or secret information , or combination of more than one of these....

 mechanism, which enables quick release.

Use in sexual bondage

For sexual bondage plays a body belt is usually called a bondage belt. Though it is not a physical restraint

Physical restraint

Physical restraint refers to the practice of rendering people harmless, helpless or keeping them in captivity by means such as handcuffs, fetters, straitjackets, ropes, straps, or other forms of physical restraint...

 by itself, it can be used to provide an anchoring point for other restraints, such as bondage cuffs

Bondage cuffs

Bondage cuffs are restraints designed for use in sexual bondage situations. Compared to conventional handcuffs, they are wide wrist and ankle restraints generally made of leather, often padded with soft leather or fake fur. Bondage cuffs may be fastened at the wrists and/or ankles by a locking...

, rope, etc. Lengths of simple leather strapping with buckles are sometimes also referred to as bondage belts, because they can be used quickly to bind limbs.

Most bondage belts are made of fabric or leather

Leather

Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...

as these materials tend to be more comfortable and better distribute pressure over the skin.