Abstract: An apparatus employing ultrasonic waves includes an ultrasonic transducer to which a solid buffer rod is attached. The ultrasonic waves are focused by liquid-filled lenses placed between the transducer and buffer rod. The ultrasonic waves are collimated by either employing a buffer rod with a spherical tip or using a plurality of liquid-filled lenses appropriately arranged. The buffer rod may be constructed of polystyrene or aluminum and the liquid-filled lenses may be constructed of glycerin or mercury, respectively. An alternative form of the invention includes a liquid-filled buffer rod and focusing and collimating means of solid materials.