Keuffel & Esser wood T-square. Excellent condition. Model 8819C-30. The patent number is etched into the wooden handle, and the patent number dates to 1943. The company name, model number, and "MADE IN U.S.A." are also etched into the wood. The handle is 32 1/2" long. The head is 13" wide. This belonged to my great grandparents, and has been in our family ever since. This has also had very little use. Smoke-free home. Pet-free home.