now commercially available infeed units that are more efficient and easier to use. Downdraft tables: Used to draw harmful dust particles away from the user without obstructing the user's movement or productivity. : Table saws commonly have a fence (guide) running from the front of the table (the side nearest the operator) to the back, parallel to the cutting plane of the blade. The distance of the fence from the blade can be adjusted, which determines where on the workpiece the cut is made. The fence is commonly called a "rip fence" referring to its use in guiding the workpiece during the process of making a rip cut. Most table saws come standard with a rip fence, but some high end saws are available without a fence so a fence of the user's choice can be purchased separately. Featherboard: Featherboards are used to keep wood against the rip fence. They can be a single spring, or many springs, as made from wood in many shops. They are held in place by high strength magnets, clamps, or expansion bars in the miter slot. Hold down: The circular sawblade of a tablesaw will pick up a piece of wood if not held down. Hold downs can be a vertical version of featherboards, attached to a fence with magnets or clamps. Another type of hold down uses wheels on a spring-loaded mechanism to push down on a workpiece as it is guided past the blade. Sub fence: A piece of wood clamped to the rip fence allows a dado set to cut into the rip fence, allowing rabbet cuts with a dado blade. Miter gauge: The table has one or two slots (grooves) running from front to back, also parallel to the cutting plane of the blade. These miter slots (or miter grooves) are used to position and guide either a miter gauge (also known as a crosscut fence) or crosscut sled. The miter gauge is usually set to be at 90 degrees to the plane of the blade's cut, to cause the cut made in the workpiece to be made at a right angle. The miter gauge can also be adjusted to cause the cut to be made at a precisely controlled angle (a so-called miter cut). Crosscut sled: A crosscut sled is generally used to hold the workpiece at a fixed 90 degree angle to the blade, allowing precise repeatable cuts