Kohler HydroRail shower column, part# 45906-CP. BRAND NEW Kohler, part# 45906-CP, HydroRail-S Shower Column for Showerhead and Handshower Functionality. Includes Slidebar Bracket for Handshower. This Column lets you customize your shower with a showerhead and handshower (these items are not included with the 45906-CP). It is designed for new installations or retrofit to replace an existing installed shower arm without cutting into your wall. The slidebar bracket allows you to adjust height and angle of the handshower. The diverter at the base of the column makes for easy toggling between handshower and showerhead. The HydroRail shower column turns your shower into a spa-like retreat without having to go behind the wall to reroute plumbing or change out the valve. The column mounts to existing plumbing, which means you simply remove the old shower arm and replace it with the HydroRail shower column. Kohler HydroRail shower column, part# 45906-CP.