My old dog finally learned a new trick and has started using these.  I was afraid he might not be able to see well enough to try but he finally did and he's getting better at them every day.  The carpet gives him a better grip and they are heavy weight enough to be stable even under his 25 lb body.  They are just high enough to help him down and back onto the bed without me having to get out of bed every time he feels like a late night drink of water.