The Sonicaid FD2 - Rate Display Doppler is a top of the range handheld rate display with high sensitivity interchangeable probes. It consists of a 2MHz for general obstetric use, a 3MHz suited for detecting the fetal heart in early gestations, and five other probes for vascular applications. An integrated data output allows a hard copy print out of the FHR trace to be obtained when connected to the Dopplex Printa. It has a probe connector for its interchangeable 2MHz, 3MHz, 4, 5, 8, EZ8 and 10MHz vascular probes. The unique fetal heart rate processing modes accounts for optimum performance in the widest range of signal conditions providing real time fetal heart rate data output. It also features an event marker for recording fetal movements when connected to the Dopplex Printa.