Similar to that of the arm, the riser rail allows you to move the shower head to the height you desire. The difference with the bar is the water supply line is hooked to a flexible supply line and then to the shower head. The head is held in place on the bar by a movable holder. The holder is similar to the one the on a permanent placement shower head, except it connects to the bar and can be positioned anywhere along the vertical bar. There is a fastener that allows you to loosen it to move it into position and tighten it in place. This type of bar can come together as a complete package with the shower head, or you can purchase it to work along with a hand held shower head already installed in your shower. They can be very inexpensive to purchase, and make a world of difference in the family bathroom.