This Twin Loft Bed with Desk is made of very thick Solid Pine Wood, and not flimsy, wobbly, or shaky. The outer dimensions are 82"L x 43"W x 70"H. The desk is 30 inches from the floor and is 76 inches wide. The top bunk has a weight limit of 300LBS and a Twin Mattress not exceeding 8.5 inches in thickness is needed for the top bunk.