Sleepsacks are a type of bondage (BDSM) gear. Sleepsacks are primarily used to confine a person comfortably for an extended period of time.[1] Similar to a conventional sleeping bag, a person climbs into a sleepsack and is usually zipped into it up to their neck. Generally, sleepsacks are very tight on the body, much like mummification, which adds to the total encasement aspect of the experience.