A separation duct for encompassing an elongate member. The duct includes longitudinal internal spacers extend longitudinally in a direction of a longitudinal axis of the duct. A longitudinal plane for each spacer is substantially parallel to the longitudinal plane of the other spacers. The spacers support the elongate member and resist slippage of the duct relative to the elongate member. The duct may be used to provide separation and protection for elongate members of a range of outside dimensions.