For knitters and sewers. Easy to use and saves time and money. An essential tool for marking buttonholes and seam allowances, tracing and reproducing diagrams for knitting patterns, altering waist, hips and crotch of patterns and changing necklines and hems. The ruler curve works perfectly for rounding out square corners on collars, cuffs, pockets, etc. Metric and imperial measurements. Suggested uses: straight ruler, square ruler, french curve, buttonhole guides, seam allowance slots at 1.5 or 2.5 cm (5/8" or 1").