Powerful, portable and reliable…Oztec gas power units, provide ultimate and immediate adaptability on the job. Utilizing rugged and dependable Honda gasoline engines, coupled to our "speed-up" transmission, vibrator heads develop 12,000 vpm and never drop below 10,000vpm...Even in the heaviest low slump concrete loads. (Tested in near 0 slump concrete). This 10,000 - 12,000vpm range is essential for high-quality concrete. (Direct drive units "scream", have short lives and usually drop below 10,000vpm when the head is immersed in concrete).