3-1/2" tapered newel posts are offered with a square or round bottom. Square bottom newel posts have a 3-1/2" square base and a 2-1/2" pin top dia. Round bottom newel posts have a 3-7/16" dia base and a 2-1/2" dia pin top dia. Tapered wood newel posts are sold unfinished and manufactured by Kinzel Wood Products. Proudly Made in USA. Please contact us about custom sizes 1-866-683-2025.