This Plug-In Flashtube Pro 400 from Elinchrom is a replacement or spare lamp for the Quadra Pro and Quadra S flash heads. With a simple plug-in connector, this flashtube can be replaced in an instant to breathe new life into your fixture. Protective gloves or an insulated tissue must be used during installation, as any contact with your skin may result in dark markings once the lamp is on.