The SR 507 supplied-air attachment is designed for connection to Sundström hoods, visors and helmets. It can also be used with an SR200 full face mask. This means that the Sundström head-tops can be used with continuous-flow supplied air. The SR 507 is made of materials which are not liable to give rise to friction sparking, which enables the attachment to be used in an explosive or flammable environment. The flow meter and warning whistle for temporary and continuous monitoring of the airflow rate is included. The control valve mounted on the user’s belt is included.