I did my first round of seed starting in the standard cell trays and as usual I was disappointed in how soon their roots were circling. So for my later planting I ran across the Epic ones with air pruning. They are heavy duty and they advertise them as being lifetime products. Which is good as they are expensive.
The photos show the 4 cell 3" deep tray. They also have a smaller 6 cell and a larger 4" deep. The watermelon seeds were planted June 21 and the pics are July 25. You can see no circling roots and the other pic shows the ball busted open showing its not root bound. The tiny melons were a surprise but the ones I planted in the garden 2 weeks ago are spread out 4 feet now and growing happy.
I also did okra in those and performed as well. I wasn’t sure if they would dry out too fast with the slits. But even after leaving them way past the transplanting date, they still made it a day in the hot sun without drying out completely.
Very happy with them and I ordered the smaller ones to start my collards for the fall.