Brown ceramic/porcelain insulators were commonly used because the brown glaze helped protect the insulator from dirt, soot, and other environmental contaminants. Brown ceramic insulators were extensively used in the construction of electrical power transmission and distribution lines.
This insulator is in very good vintage condition. There is some variation to the brown color in spots, but there are no chips or cracks. There is a small flat spot near the top that has light/white edges to it, but this is obviously a manufacturing defect (see pictures).
Approximate Dimensions: 3.5"T x 3.25" in diameter at the base