Many homes have staircases that aren't bordered by a wall. In this case the Y spindle aids installation of the pressure mounted gates to these types of staircases. The Y spindle wraps around the baluster to provide a secure installation. On the Gateway®, use Y spindles only on the hinge side of the gate. No more than 2 per gate can be used. On the Center Gateway® models, the Y spindle can be used on either side of the gate. However, they must be used on the same side. No more than 2 per gate can be used. NOTE: For installation of a pressure-mounted gate on a staircase with ballusters on both sides, you will need to use a K10 Installation Kit. See Gate Selection Chart on Kidproteq's Home Page