If you use it in a rectangle shape, they actually make a top for it. If you put NIC grids on it as a top, at 30 inches tall it won’t be easy to clean (or open) and wouldn’t really lend itself to you sitting in there with your bunny it you wanted to. You could attach a sheet to the top but would have to detach it every time you need to clean. If you had already gotten it and then ran into a problem you could do these things to cope. Only my opinion, but I’d try to anticipate the possibilities (what if the bunny is a jumper, what if you ever wanted yo use the xpen for another bunny that may be a jumper, what if you wanted to add a shelf fir bunny to lounge on, etc). I know I went for overkill (all are 48 inches tall), but one day I might be able to bond my single bun with my bonded pair so all three can live in our xpenned area and my single bun is a jumper. Also, many online retailers offer free shipping . . . on ebay, you may save on the purchase but will likely lose the savings in shipping costs.