Most older or inexpensive pieces of furniture and cabinets use wooden sliders, upon which the drawer slides as it is opened or closed. Wood slides can be lubricated with paraffin wax. Newer furniture and cabinets may use plastic friction slides, or more elaborate bearings slide, which will provide smoother operation with less binding. There are different types of bearing slides, such as linear ball-bearing slides, roller bearing slides, progressive action slides. Modern drawer slides are usually categorized in how they are mounted, including center mount, side mount, bottom mount and European mount drawer slides. Drawer slides are intended for use varying from light to heavy drawers and thus contain load ratings ranging from 75–450 pounds (34–204 kg). A load rating of 100 pounds (45 kg) is considered typical.[citation needed]Drawer slides often have a mechanism to keep the drawer from accidentally being pulled fully from its enclosure