Wood Box Newel - Plain Style with Pedestal - 48" Tall - Elegant Sleeve Design - Staircase Post (Red Oak)

What is the width size?

Will this slide over an existing smaller circular newal that is already in place? Looking for a replacement to go over top of an existing newal.

if the base is 4.5", why does description say 3.5"?

What is the width of this post at its widest? I know the bottom trim is 4-1/2" wide, but the top trim looks wider.