Under handrail lighting exceeded my expectations!!! During handrail construction, I ran low voltage wiring thru the posts and into the top rail and out the bottom of the top rail. Measured and cut Roma XL black LED channel track to length for each opening. Used 3M's Heavy Duty outdoor double faced tape to attach Roma XL channels to underside of rail. Installed LED string lights (200+ connections across 54' of handrails). Custom cut "black" diffuser cover to fit each track. LED lights are on a dimmer switch. When lights are off everything showing is black. Which makes tracks invisible to the eye and appears to be part of the actual handrail. Looks absolutely fantastic, very high end look. Important thing is to run the low voltage wiring during handrail assembly. Could not be happier with the result.