The patented door design of A.C.T. dust collectors is simple, fast and secure. The cast aluminum handle locks the door shut against the dust collector. The heavy-duty cross-rod and brackets on the dust collector and cam are all stainless steel. Knobs, hinges, springs, threads and wasted time are eliminated. Lift the handle and door comes off. Set the cross-rod in the brackets, lower the handle and it's locked securely. Click Here to watch the video.