Pulse-Bac vacuums mark a new standard in Dust Extraction and jobsite Dust Collection. The 550H-ATO is great for general cleanup of dust and debris, but is designed to collect capture and control dust generated by hand held power tools. Standard shop vacuums can lose up to 50% of their suction after collecting as little as 20 Gal. of material. Not Pulse-Bac, it's the only vacuum with patented Pulse-Bac Automatic Pulse-Clean Technology. Pulse-Bac technology pulses air back through the filters, keeping them clean and suction consistent from the start of the day to the end of the day and it's 100% automatic, no buttons or levers to push. Pulse-Bac is made for the tough conditions of the job-site. The 550H ATO has a powder coated 16-Gauge cold-rolled steel tank and a tough ABS plastic hood, but our quality doesn?t stop on the outside, open up a 550H ATO and under the hood you?ll find the mechanics are made from galvanized metal and ABS, all components are designed to stand up to rigorous use. Whether your job involves dust from concrete, wood, drywall, metal or any other material, Pulse-Bac will help you do it in a cleaner and healthier environment. The 550H ATO includes the Auto Tool Start feature. Simply plug the tool in to the outlet on the back of the vacuum and you're ready to go. When the tool starts the vacuum will start automatically. The 550H ATO is a HEPA Certified Vacuum that meets EPA RRP requirements when working with hazardous materials like Lead and Asbestos.