I'd rate this closer to 3.5 if I could. My 4.5 lb dog has just started to use the stairs after looking at them for about a week. He's still timid and feels a little unsteady, but he's jumped into bed a couple times on his own. My 16 lb dog, however, won't even look at the stairs. I've guided her on them a few times and she's very unstable. I think it would still be safe for her to use them, but she disagrees. I still have to wake up multiple times a night to lift her on my bed. Worth it for being fairly visually appealing and somewhat helpful for a toy (or really, more "teacup" sized dog), but very hit or miss beyond that. And a little pricey for how unstable it is.