Zenith Respirator Cal. 2552 PC/2562 PC. This model requires a special tool to open it. Serial 026E902 Case Gold plated with some marks/scratches consistent with its age. Dial Original. Hands Believed to be original. Crown Believed to be original Bracelet Original Zenith NSA. Service History Unknown. Price 550 GBP plus shipping at cost (Paypal add 3.4%) or 965 AUD plus shipping at cost (bank transfer only) The watch is located in Australia.