Suspension harness
From wipipedia.org
A supension harness is an arrangement of straps used to support a person during suspension bondage. Suspension harnesses are based on the safety equipment used by climbers and steeplejacks. When used properly, they will allow a person to be suspended safely for a period of time without affecting circulation or breathing. Suspension harnesses are usually used in conjunction with a suspension bar and a hoist.
It is important to ensure that the harness is comfortable at the start of the suspension, as the slightest discomfort may become unbearable after an hour or two.