1)casement four-bar hinge or five-bar hinge 2)different styles avalible: a)avalible in 8inch,12inch,14inch,16inch,18inch and 28inch b)round groove and square groove c)18mm base(botton groove) and 22mm base d)friction arm thickness: 2.0mm,2.5mm,3.0mm 3)mainly used for outward-opening casement window 4)material : stainless steel