 Stage pin connectors are specified by United States Institute for Theatre Technology standard "USITT S3-1997 Standard for Stage Pin Connectors".Many theatres also use NEMA connectors, which are the standard connector used in homes and businesses in North America, because of their availability and the ability to connect household fixtures to a theatrical control system.Twist-lock connectors are used in many theatres because of their locking feature, which will not allow fixtures to become accidentally disconnected.