Standard outlets require the user to insert or push in the plug for it to connect. Twist lock receptacles add an extra layer of protection by requiring the user to twist the plug for it to properly connect. This secures the plug in place, making it difficult to accidentally pull the plug free from the receptacle. Twist lock receptacles often see use in areas where equipment must stay on or connected for operation. They also see use in semi-permanent operations or locations where a plug should not be easily unplugged due to vibration.