The Sonicaid Digital SR2/SR3 high sensitivity handheld Dopplers with fixed 2MHz or 3MHz are intended for general purpose screening of the fetal heart during all stages of pregnancy from as early as 8-10 weeks, right through to labor. The attached probes are waterproof (IPX7) for high sensitivity FHR detection in both normal use and in waterbirth monitoring and offer dynamic digital noise reduction.