Longest 60" hollowing bar 1.25" diameter with 48" long milled slot for bearing, 6" deep 3/4" hole in one end with set screws. The back of the bar has a 2" deep 3/4" hole with setscrews for an extension or an end handle.. Needed for hollowing beyond 24". Also consider longer laser holder.
The current version of the hollowing bars and extensions are drilled and fitted with setscrews to accept the extension or handle. Now any hollowing bar can accept an extension or end handle. Earlier versions were not drilled and fitted with the set screws so if an extension or handle is desired, the bar will have to be machined.