made of Acrylic board, ,Flat,one side was Black flannel to prevent reflection
Advantages of acrylic material:Long life, strong impact resistance, light weight.
and Good weather resistance, acid and alkali resistance
So it is stronger than plastic one,lighter and cheaper than metal one,great choice.
Thickness:2.2mm
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)
and Un-drilled board,you can DIY.
weighing about 60g.