When building a project that is a square or rectangle, it’s essential to build against straps that in a 90-degree angle. Doing so ensures that your project is in the intended shape when completed. Straps can also be used to ensure your project is the proper size when finished. We do not sell straps. They can be purchased from your local hardware store. [Here is a link](https://www.homedepot.com/p/Waddell-36-in-x-3-4-in-Hardwood-Square-Dowel-8312U/100536762) to the product we purchase at Home Depot.