The LifeDop 250 is a full-featured handheld device with a large display that indicates heart rate, battery status, and signal strength. A general-purpose obstetrical probe for early fetal heartbeat detection through delivery. Wide-angle beam eases the time spent hunting for the heartbeat. Once detected, the sound is clearer than ever. The LifeDop 250 accepts all LifeDop nondirectional probes. With 3 MHz probe.