hi catherine, just came back to update you on my PUL cover, i just put Archie to bed with the hugest thickest terry nappy on and the MotherEase Airflow cover fitted well, still had heaps of room left in it. the nappy is so thick that arch can hardly walk, he was running up the hallway in fits if laughter cause the nappy was so thinck it made him run really funny, lol!