Bonsai Outlet 9 1/2"- Humidity Tray

What is the depth of each of the bonsai outlet trays? (widths of 7 1/2, 8 1/2, 9 1/2, 11 1/2, and 16 1/2 inches)? also the heights for pebbles.

is this tray plastic?

Are these trays square or rectangle? If rectangle what are the dimensions of the 11 1/2 “ tray (length x width)?

What are the measurements of the 7” tray?