The Japanese metric measuring wheels are available at my Etsy shop.

http://www.etsy.com/shop/sacurve

At the end of August, I will have a measuring wheel available in inches.

Measuring wheels are handy for measuring curved lines on patterns. Comparing an armhole length to a sleeve head will give you the amount of ease built into the sleeve. I find them especially handy if you have done fit changes and need to see how those changes affected your pattern.

Happy Sewing!

Claire