ModRail – Articulating Flat UnionThis articulating union is the component that attaches to a ModRail post and allows you to attach a flat top hand grab. This union is used for posts that are on stairs or ramps and will articulate to any stair or ramp angle. This union screws into the top of the post and making its height adjustable. Material is Type 316 stainless steel. The finish is satin polish.