Use the 78-cell side to perfectly fit 1.5" A-OK StarterTM plugs or round MacroplugsTM. Use the mesh side for sheets of A-OK's, Mini-Blocks, or Gro-Blocks.
The tray fits in a standard 10x20 flat and keeps the Grodan elevated from the bottom of the flat. Easily sanitize as any hard-plastic product; even dish-washer safe!