Metal bondage is bondage involving the use of metal apparatus to restrain a submissive as part of BDSM activities. In contrast to the use of rope to secure a body, metal bondage normally requires careful preparation, since more extravagant devices have either to be built or bought from a specialist. The range of devices can vary significantly, from simple handcuffs or chains to specifically designed chairs or complex bar linkages. Chains are occasionally preferred for suspension due to their strong nature and ability to hold large amounts of weight including various other objects on top of the person being suspended. Because they feel cold to touch and rattle and clank chains add auditory and tactile sensory stimulation to the bondage scene, and can similarly be used to enhance the atmosphere of a dungeon.