encitech D Type Accessories Knurl head screw 614014 - Encitech 2099-0002-21, The knurl head screw manufactured by Encitech, model number 2099-0002-21, is made of metal and comes in a single piece bulk packaging. It features a knurled head, which facilitates easy gripping and manual tightening or loosening without tools. This type of screw is typically used in electronic enclosures and other applications where frequent access is needed without the use of tools. Encitech 2099-0002-21 FRS1/5-M2.5 Knurl Head Screw metal 1pc.