This device converts your electric drill into a sheet metal nibbling tool. It can be used to cut and trim steel or aluminum siding, roofing material, fiberglass sheeting, etc up to 16 ga steel, 14 ga aluminum, 14 ga fiberglass. You can make complex cuts and curves, or follow a straight-edge for clean straight cuts. I had a van that I had a fiber stand-up top installed on. The guy used a tool just like this to cut the original top from the van. I was really surprised by the versatility of this tool. Unlike the ragged cut of a sabresaw, this tool leaves clean cuts. It came with extra tip and replacement cutter too. This will be a treasured tool in my toolset.