In many cultures, jewellery is used as a temporary body modifier, with, in some cases, hooks or even objects as large as bike bars being placed into the recipient's skin. Although this procedure is often carried out by tribal or semi-tribal groups, often acting under a trance during religious ceremonies, this practice has seeped into western culture. Many extreme-jewellery shops now cater to people wanting large hooks or spikes set into their skin. Most often, these hooks are used in conjunction with pulleys to hoist the recipient into the air. This practice is said to give an erotic feeling to the person and some couples have even performed their marriage ceremony whilst being suspended by hooks.