Built-in speaker
2. Three working mode: Real-time FHR Display Mode, Averaged FHR Display Mode and Manual Mode
3. LCD screen
4. Battery status indication
5. Auto shut off if there is no signal within 1 minute
6. High sensitive doppler probe, 2.0Mhz / 3.0Mhz can be choosed
7. Low consumption, two AALR6 batteries can last more than 8 hours for normal use
8. Pluggable USB probe interface, probe can be replaced