Precise Measurement: Each ruler features a non-slip surface with 1/4in seam allowance and marked points for easy, accurate positioning. Measurements are highly precise from point to point. High-Quality & Patented: Made of premium, high-temperature resistant resin plastic and patented in the USA for durability and long-lasting use. Heat-Resistant: Withstands temperatures up to 428°F/220°C and tolerates short - term ironing up to 536°F/280°C. The ruler will remain hot for a few seconds after ironing. Translucent Design: See fabric underneath for precise placement. Fold fabric over the ruler to the desired hem depth for faster, more accurate pressing. Versatile Shapes: Includes 5 shapes—Hexagon, Pentagon, Diamond, Triangle, and Circle—perfect for ironing and shaping different fabric patterns. Each ruler measures 3 inches.