I ordered two of these trundle platform beds my four grandchildren.  Although one of the beds was lost or stolen en route, Wayfair was willing to send a replacement at once.  I was impressed with both their customer service and the quality of the purchase.  These are study, well-made beds.  They weren't difficult to assemble.  The trundles have wheels which roll easily.  We bought an 8-inch mattress for the twin bed and a six-inch for the trundle.  There is still plenty of room for the trundle to fit underneath the twin.  I'm completely satisfied with the purchase.