It does take up a large footprint on the floor. Could have gone with a medium for my Rottweiler (94#), but she's quite happy on the "Large" version that I ordered (laying on her side, two of her could fit on it). Pressing on the foam under her shoulders, I found that there was still enough foam to support her body - she's not touching the hard floor - very good!I have a Prime account (free shipping), but found another site that offered free shipping and a reduced cost -- very happy with the value, speed of delivery, and packing offered through Pxx Sxxxxxxxx.Viewed crib mattresses, and found it daunting -- and expensive! More expensive and not always from products that could guarantee that they would not emit some sort of fume.Online reviews of foam made from bio-based materials suggest that they are being used in automobile seating. Really great to have this type of product available for pets too.Zip off cover, and faux leather air breathers on sides to expel air when she lays on it. All items are made from recycled products. Poly fill from plastic bottle recycling plant; and memory foam is also 'green' - using bio-based materials (soy instead of petroleum). Most important - no odor, and she loves it. I can lay on it with her - even I am comfortable. I highly recommend purchasing this item for your pet.