A seam allowance ruler allows you to quickly place a magnetic seam guide on a sewing machine by lining up the needle with the seam allowance measurement you'd like and then placing the magnetic guide on the edge of the ruler. The seam allowances range from 1/8" to 2" with each 1/8" increment in between. There is an additional hole for a scant 1/4" seam allowance.

Additionally, one side of the ruler can be used as a 5 1/2" ruler while the shorter side can be used for up to 2 1/2". A 45 degree line is also available for doing things that you can do with a 45 degree line.

Or just the bullet points:

• Seam allowance guide holes for 1/8" to 2" (With each 1/8" in between)
• Seam allowance guide hole for a scant 1/4"
• 5 1/2" ruler
• 2 1/2" ruler
• 45 degree guide line