Made of aluminum, anodized black ,Flat,
So it is stronger for your expensive and heavy lens.
Size:140x140mm,Thickness:2.0mm
There are 5 sizes for your choice,fit more need.
#00(inner Dia.26mm)
#0(inner Dia.35mm)
#1(inner Dia.42mm)
#2(inner Dia.52mm)
#3(inner Dia.65mm)
weighing about :96g.