Altar candles are candles set on or near altars for religious ceremonies. Various denominations have regulations or traditions regarding the number and type of candles used, and when they are lit or extinguished during the services. Altar candles may sit directly on the altar or be placed in tall stands to the side of or behind the altar. For safety, altar candles are secured in some type of candle holder which may be simple or elaborate. To prevent wax from dripping, candles are often topped by a "candle follower", a short tube made of brass, glass or some other non-flammable material.