Mayes 10005 Brass Rafter and Stair Gauge (2 Piece Set)

The 2 Piece Brass Rafter & Stair Gauge by Mayes simplifies rafter patterns. Use a rafter or framing square to find your angle, then screw on the gauges, and your pattern is ready to repeat. Sure-grip thumbscrews keep the pattern from moving. It's made of solid brass, so it won’t wear out.