Great Little unit that served our needs for incubating Uromastyx eggs. You can get MANY clutches stacked or go with the minimum of 2 trays a shelf and get at least 6. This incubator is perfect for small reptile eggs. I wouldn't want to try to incubate more than one or two clutches of Ball Python or larger eggs. I use a hatch tupperware that is 7.09 x 5.12 x 1.97 inches in mine, side to side on each shelf and the bottom tray. Worth the investment for small hobby breeding.