From their forums:
This set contains 3 Holo Ads made out of HDF and 3mm thick transparent acrylic.
Holder is made out of HDF
Holoboard is made of 3mm thick transparent acrylic with high quality print.
You can find two types of holo Ads
One bigger:
Length: 12 cm / 4.7"
Height: 12.5 cm / 5"
Two smaller:
Length: 7.3 cm / 2.9"
Height: 12 cm / 4.7"