The product is a vintage sliding T-bevel square manufactured by CHALLENGE CUTLERY CORP. in the United States during the early 1900s. It features a patent applied for design and is an antique original without any modifications. This tool would have been used by carpenters and woodworkers for precision cuts and measurements in woodworking projects. Its unique design and historical significance make it a valuable collectible for those interested in vintage tools and hardware. In as found unclean condition. Please look at the pictures as they are part of the description and ask questions if you need before you bid.  This is a no reserve auction So good luck bidders