This Twin over Full Bunk Bed sleeps 3 adults. It is made of very thick Solid Pine Wood, and not flimsy, wobbly, or shaky. The outer dimensions are 82"L x 58"W x 70"H. The top bunk has a weight limit of 300LBS and the bottom bunk has a weight limit of 600LBS. A Twin size Mattress not exceeding 8.5 inches in thickness is needed for the top bunk and a Full size Mattress 10-11 inches in thickness is recommended for the bottom bunk.