WingIts' Diamond Knurled Stainless Steel Grab Bars. These Premium Decorative Grab Bars are designed from 304 (18/8) stainless steel with concealed flange covers. Designed to ensure a great grip AND still be easy to clean with knurling cuts in a diamond-shaped crosshatch on the surface of the bar. Diamond Knurled Grab Bars come with stainless steel screws to install into structural blocking (reinforcement behind the wall). For Hollow Wall applications use WingIts' Grab Bar Fastening System - the World’s Strongest Fasteners. WingIts become completely waterproof as they are tightened, even over grout lines! For Ceramic Wall Tile or Marble, use the Apache200 Drill Bit (WA200GTS34) to drill through the material easily with your cordless drill (rated up to 200 holes in ceramic wall tile). For the Worlds' Strongest Fasteners and Fixtures - look for WingIts. Our reputation hangs on EVERY Grab Bar we offer!