
File No.: QR-HC21-C-C09
Xiamen Linktop Technology Co., Ltd.
Page 6 of 17
In the working mode, short press the button to enter sleep mode
In the working mode, double press the button to switch auscultation mode
(heart sound auscultation and lung sound auscultation mode)
Green light is always on in lung sound auscultation mode when Bluetooth
connected
Green light flashes slowly when charging
Green light is always on when fully charged
Blue light is always on in heart sound auscultation mode when Bluetooth
connected
2.4 Specifications
Product Name
Electronic Stethoscope
Model
HC-21
Power supply
5V DC 500mA (lithium-ion battery)
Dimensions
Height 1.02 inches (26mm)
Base diameter 1.77 inches (45 mm)
Membrane diameter 1.7 inches (43.8 mm)
Weight
62g
Battery life
More than 500 charging cycles
Frequency range
RF: ISM, 2.402-2.480GHz
Attenuation
100Hz-500Hz ≤ 12dB
600Hz-1000Hz ≤ 20dB
Modulation
GFSK
RF power
4.5 dBm
Bluetooth version
Bluetooth 5.0
Type of application
parts applied
BF
Protection class
IP22
3. USING INSTRUCTIONS
3.1 Preparations for use
3.1.1 Application
Prior to using the stethoscope, it is necessary to confirm whether your mobile phone is
supported by stethoscope. The available mobile phones are as follows:
(1) Mobile phone or tablet with Android 7.0 or higher and Bluetooth 4.2,
(2) iPhone that supports Bluetooth 4.2, such as: iPhone 7 / 7 Plus / 8 / 8 Plus / X / XR / Xs /
Xs Max / 11 pro / 11 pro Max / 12 mini / 12 / 12 pro / 12 pro Max.
Note: Always use the most recent version of the application (
"NexStetho" application)
. You
can download it from Official website:
https://www.linktop.com
, Google Play or App Store.