1.pocke1,hand-hold,use conveniently; 2. Cassette holder for sensor,safety in carry,frame in bend,esily for operation,also comfortable for pregnantwoman; 3. Value or curve in LCD display; 4. With data and time or timer function; 5.Ultrasound sensor can be reptaced; 6.With inner loudhailer; 7.Better power management function; 8.With video output port; 9.Can monitor pregnant woman's SPO2 and pulse(in option); 10.DSP technology,work frequency in 1MHz,ultrasound dosage is far less than safe standard of monitoring fetal,is more satety;single lithium battery,with battery state indication