A holder is used in dishwashers, it is known as the dishrack stop kit. This kit comes with both the front and the rear stop, these parts are installed at either end of the rails that the upper rack slides on. These stops help keep the rack on the rail, without this part the upper rack of your dishwasher will not slide in and out of your dishwasher properly. If you need to fix both the left and right rail you will need to order two kits. To install this part, you will need to remove the upper rack from your dishwasher, and you may need a flathead screwdriver. These front and rear rack stops are made of plastic and they are gray in color.