Easy to assemble without instructions. I ordered the biggest one, and boy was it big. I could curl up on it and take a nap myself, if my dog wouldn't get mad. Speaking of which, the second I threw her blanket on top of this she climbed on top and looked back at me, wagging her tail gratefully. It has Just enough give to make it comfy. Assembly was a breeze: I didn't even look at instructions, and it came with the necessary allen wrench. It's pretty obvious if the tubes are snapped together the wrong way. Great product at a great sale price!