Tanning booths (also known as stand-up sunbeds) are vertical enclosures; the tanner stands during exposure, hanging onto straps or handrails, and is surrounded by tanning bulbs. In most models, the tanner closes a door, but there are open designs too. Some booths use the same electronics and lamps as tanning beds, but most have more lamps and are likely to use 100–160 watt lamps. They often have a maximum session of 7–15 minutes. There are other technical differences, or degrees of intensity, but for all practical intents, their function and safety are the same as a horizontal bed. Booths have a smaller footprint, which some commercial operators find useful. Some tanners prefer booths out of concern for hygiene, since the only shared surface is the floor.