SEWERS AND HANDYMEN BELIEVE IT OR NOT - I used it in sewing to measure slope of shoulders. Has inch marks on one side of plastic base and metric on other edge-Also has a magnet if using it on metal-Transfers any angle or pitch easily and accurately. Made of ABS plastic. Has a permanent ceramic magnetic base. Can also be used for Inch and metric graduations - V-groove edge fits on pipe and conduit - High-impact molded body - Easy-to-read increments read 0-90° in all four quadrants printed on durable acrylic lens - Extra-strong, ceramic magnet adheres to ferrous metal surfaces -Edge fits on pipe and conduit