The H1a hydrophone uses the same low-noise, robust transducer assembly as our other hydrophones, but does not have an internal buffer amp.  The H1a offers the following advantages:
• Low cost
• Low self noise
• Good sensitivity
• Robust design handles accidental drops and temperature extremes
• Compact (4.5mm OD) Low-noise cable with tough urethane jacket
• Very high dynamic range
• Connects directly with 1/4" TS plug to High-impedance microphone circuits and musical instrument amps
• User can buy or build preamp to focus on application-specific systems
• High-quality Neutrik gold output connector
• Compact size and easy hand of cable
• High specific gravity and streamlined shape keeps hydrophone down in currents
• 1-year limited warranty