I bought a couple of these, along with severa of Garland's "Small Budget Propagator" and a couple of 100 trays and 2" vented humidity domes. I recommend that combination for several reasons:
* Except for color, the trays for the Small High Dome Propagator and the Small Budget Propagator are exactly the same. They seem to be made in the same molds, and are both almost as sturdy as Legos (but their rounded corners would make the trays much less painful to step on).
* The lids on the Small Budget Propagator are not vented, so they function well as drip trays for the Small High Dome Propagator.
* Three of these fit easily into a 1020 drip tray, without interfering with the humidity dome.
* You can grow within a 1020 tray and 2" vented humidity dome until your crop gets to be too tall, then put the tray into the lid from the Small Budget Propagator, and put the High Dome on top.
Except for the depth, these are an ideal size for growing microgreens. The Small High Dome Propagator is everything I hoped it would be. I have grown a crop of daikon microgreens in one, and now I'm growing some sunflower shoots.