Bought two of the retro covers inflated fully about 1.5 psi inside the tube, it all feels sturdy, my kids were impressed when we arrived at the snow hill until the first run. We went up but could not get it to glide down the hill, my son in a cheap plastic inflatable flew down the hill, my daughter in her plastic red sled went flying down. I kept getting almost glued to the hill the tube wouldn’t slide even when getting pushed off. I suppose if the track was icy I would have gotten some speed, bSee full review