The Stainless Adjustable Handrail Support is specifically designed to fit a 1.66" diameter newel post. It offers versatility and convenience by allowing for easy adjustment and positioning of the handrail. The support is available in two stainless steel grades: 303 Interior Grade for indoor applications and 316 Exterior Grade for outdoor or corrosive environments. Both grades offer excellent durability and resistance to rust and corrosion. Choose the appropriate grade based on the intended application of your handrail system.