friction stays, window hinge, bar hinge, window accessories.18mm square groove, 1.0mm groove thickness, 16mm bar width, with stainless steel slide. material:SUS 201,SUS 202,SUS 301,SUS 304( onver 7.5percentage nickel, 17.5 percentage chrome). 8 inch to 14 inch usually 4 bars. over 16 inchusually 5 bars or 6 bars.