Precious Tails Sherpa High Density Foam 4 Steps Stairs are great for dogs and cats to access couches, beds and cars. Most importantly they will help pets with joint or aging problems to access their beloved spots. These stairs are also ideal for pets who have not learned how to hop up to be by your side. The interior of these stairs are made with premium high density foam with a sherpa/microsuede cover that features non-skid bottom. The removable cover zips off easily so it can be machine washed. The foam is light in weight but strong enough for pets to run up and down without sinking in. The high density foam is soft on your pet's feet and easy on the joints. The stairs can be easily moved around your home due to it's light weight. Best of all there is no assembly required! We recommend these stairs for smaller pets up to 50 lb.