Usually located at each bed-head, they feature a large orange button, which is used by patients when in need of assistance. Staff attending a call can raise a more urgent staff-to-staff call to summon help if necessary and a third call level, crash call, can be used for medical emergencies. They have a socket for a push-to-call extension lead (NET206) that is monitored in case the lead is pulled out from its socket inadvertently. The staff operations on this call unit are controlled by a magnetic key (NET216). The reset button can also be used to log a visit to a room and also register the nurses presence within the room. A reassurance light is illuminated red to reassure a call has been made and green to inform the patient that staff are on their way.