description 4-stroke gas backpack concrete vibrator the oztec bp-50a 4-stroke gas backpack concrete vibrator is 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 12000 vpm and never drop below 10000vpm. even in the heaviest low slump concrete loads. (tested in near 0 slump concrete). this 10000 - 12000vpm range is essential for high-quality concrete. direct drive units "scream" have short lives and usually drop below 10000vpm when the head is immersed in concrete. california proposition 65 warning. features mounted on very comfortable frames oztec backpacks allow operators incredible maneuverability around the job. run time with full tank approximately 1 hour plus. bp-50a runs heads up to 2 ½" diameter. engine: honda 2.5 hp, 4 stroke the bp-50a is equipped with a totally enclosed rotary throttle and a conveniently located kill switch on the same handle specifications acme tools brand name oztec industries acme tools part number bp-50a assembled weight (lbs) 30 california proposition 65 warning required yes country of origin united states globaltradeitemnumber (gtin) 00415990001171 package contents backpack concrete vibrator package depth 12 package height 36 package weight 31 package weight (lbs) 31 power source gas upc 415990001171