Model: Beckman-Swindel Advanced Series 2000 mixed gas diving helmet.
The Advanced Air diving helmet was one of the earliest modern diving helmets. It is constructed of a lightweight and non conductive fibreglass material which was suitable for underwater cutting and welding. The helmet was originally developed by George Swindell in the 1960s and manufactured by Advanced Diving Equipment (who later merged with Beckman Instrument Company). It was distributed in US and UK through Divex.