18KHZ Variable Frequency Pulse Width Modulator 35 Amp Variable Frequency Pulse Width Modulator For Hydrogen Generators Variable from 33 HZ-18 KHZ    RARE… Big Block 502 kit W/ hho pump + 18KHZ Variable Frequency Pulse Width Modulator  = $1,493.95 Call for dealers pricing 813-931-9767 Dealers cost  $1,239.00  Our Big Block model is our  mid-  large- size and is designed for 6- 8 - cylinder vehicles 12  to 14 liter now your in control.  It has  stainless steel plates that are tuned, charged and with a total of 972 sq. inches surface area of stainless steel 316L, the Big block 502  produces approximately 1.89 liters per minute. Model: Series Big Block 502 HHO Gen Water Fill Mode: Automatic Cooling System: Air Cooled Dimensions: Height 7.625", Width 7.625" x 4.9 " Engines: 8- cylinder vehicles autos/heavey pickups:. Fuel Type: Gasoline, Ethanol, Natural Gas, Diesel