Connecting One to External Devices
If you're connecting to an input-only jack, such as the input to a wireless transmitter or a microphone input jack, simply use one of the provided male-male 3.5mm-plug cables. Plug one plug into One and the other into the input jack of your device. If you wish to monitor the output with headphones while recording, use Thinklink (see Thinklink Instructions) or preferably, an audio splitter such as this one, which is simpler than using Thinklink.
If you're connecting to a device with a "headset" jack i.e. it provides both microphone input AND headphone output in one 3.5mm jack, use Thinklink, which provides switching to facilitate changing the direction of signals - from stethoscope to device for recording and from device to headphones for playback. See the Thinklink link above.