Adopting new kind one-side sound button with patent design Special sound collection with negative camber and washer Equipping with high precision membrane and y type tube(B type) durable Special material like soft ear plug and providing different kids of colors Specification Flat shaped head is used listen low frequency heart sound extended sound, the third heart sound and the first and second heart sound YUWELL, STETHOSCOPE, SILVER Features : Adopting new kind one-side sound button with patent design Special sound collection with negative camber and washer  Equipping with high precision membrane and y type tube(B type) durable Special material like soft ear plug and providing different kids of colors Specification Flat shaped head is used listen low frequency heart sound  extended sound, the third heart sound and the first and second  heart sound