I have the 4 step model in the Doggy Steps (plastic with sheepskin covering) and it is 16 inches high and works well for my new puppy for my bed. They are on ebay put in a search for 4 step doggy steps. You can also purchase a accessory to make a 3 step into a 4 step at
www.doggysteps.com and it comes with an attachment plus a new cover.