Amplifies up to 16x (24db) over traditional acoustic scopes.
Experience the next generation in electronic stethoscopy; combining impressive acoustic amplification and electronic noise filtering with comfortable ergonomic design. All structured to help you adjust for faint heart sounds, obese patients or a louder operatory environment.

The 657 features:
• Patented piezopolymer film contact microphone provides wider frequency response than acoustic mikes used in competing models.
• Three frequency modes:
• Bell (15-200Hz) for cardiac sounds Diaphragm.
• (100-500Hz) for lung sounds.
• Extended Range (15-1000Hz).
• 8 level volume control.
• Holds last mode and volume setting for convenience.
• Auto-shut off after three minutes extends battery life.
• Battery warning LED signals when replacement needed.
• Binaurals fixed at 15º angle for snug aural fit.
• Specially constructed ADSOFT™ PVC eartips for the ultimate in wearing comfort and acoustic seal.
• Lightweight and compact—weighs under 6 oz., measures just 28”.
• Uses "AAA" battery (included).
• Made in Korea.
• 2-year warranty.

Detail Specifications:
• Power supply: 1.5V (AAA Battery)
• Electric current supply: 20mA (max)
• Battery life: 150 hours under continuous power on (approximately 3000 measurements at 3 min/per)
• Weight: 6.17 oz. (175 grams)
• Length: 29.1 in (74cm)
• Frequency: Bell (15-200Hz)
• Diaphragm: (100-500Hz)
• Wide/Extended Range: (15-1000Hz)
• Operating environment:
• Temperature: -4°F to 140°F (-20°C ~ 60°C)
• Humidity: 20 to 90% Relative humidity
• Storage environment
• Temperature: -4°F to 158°F (-20°C ~ 70°C)
• Humidity: 15 to 95% Relative humidity

Regulatory standards:
EN 60601-1 (1988) Medical electrical equipment, Part 1: General requirements of safety.
EN 60601-1-2 (1993) Medical electrical equipment, Part 1: General requirements Section 1.2
Collateral Standard: Electromagnetic Compatibility.