The 159D-RTWX replacement tips for 159D-RTW contain 2 tips and 4 screws. PTFE has outstanding resistance to chemicals and solvents. It is excellent for cleanroom use.Specs amp; FeaturesLarge Points, Soft Replaceable Tips, Application: Replacement tips for 159D-RTW, Quality: , Surface Resistivity : Insulative, Shape: Straight, Material: Acetal, Tip Width: .06 (1.5mm)