Window stayAdjust the opening angle by the small sliding sheet in the bottom groove to a fixed placeGood quality stainless steel materialRegular usage after strictly 50000 times open and close testBe suitable for U-PVC, Aluminium , wooden casement windowMaterial: S.S.301, 316, 304, 201, 202Thickness: 2.0mm, 2.5mm, 3.0mm