I foster felines, and this cage is amazing for kittens.  You can divide it into two separate cages, each with an additional half shelf, or open it for a larger litter.  It is well made, very sturdy, and the spacing on the bars is small enough to be safe for kittens.  Unlike some other cages, since it does NOT fold down you don't have the risk of kitties getting their paw pads caught if they play in the corners (I've had this happen with some 4' tall condos I have).

Great value, very durable
For some folks or situations, the fact that this does not fold down might be a negative.  As stated above, this also eliminates the risk of injury in the corners.