10x20 Inch Black Plastic 10 Pack Plant Propagation Tray – Growing Trays for Garden, Planting, Seedling, Soil & Hydroponic Horticulture - Microgreen Trays Grow Plants - No Drain Holes

They are very thin so you have to be careful of the amount of stuff with weight that goes in it to grow your seedlings

These are 10x20s and are fine when flat, supported on a table or shelf. They are watertight, as advertised. They are too flexible to be used to carry starts, however. They tend to warp however you carry them, so I use 2 or 3 at a time when potting out starts.

Works great for what I use it for. These fit perfectly on the shelves in my room, then I put the smaller planters in these trays so any dirt or water that comes out of the planters stays in the trays. Easy to use and seems durable

These trays ended up being a no for me. They are standard 1020 trays, which is the main upside, but they are extremely thin and flimsy. I had issues with them bending, dropping things, and generally not feeling stable enough when moving seedlings or supplies around. To make them useful, I often had to double or even triple them up. In several cases, I ended up moving plants or materials into better-quality trays because these just did not hold up well enough. They may work for very light-duty use, but I would not recommend them for seed starting or anything that needs regular moving, carrying, or watering. I would spend a little more on sturdier trays next time.

The basic container. Not heavy duty. Not expected to be. Double up to reduce cracking and bending