... :1,External drive;2,Self driveProduct type according to thickness:1,Thick type(T>0.5mm); 2,Standard type(0.5mm>T>0.2mm ... );3,Thin type (T<0.2mm=,Thinnest type 0.03--0.05um;Product type ... ,Smallest is diameter 8mm,Biggest is 65mm;Producttype according to type of metal plate:Brass,Nickel,Stainless steel,FerrieThree.Diaphragm Feature ...