This aider is not often available at major retailers, though it is available on the Fish website.
If you are counting your pennies (who isn't?) this is the most aider for your dollar by a large margin. You can buy five of these for the price of a pair of Petzl Wall Step Etrier. With unlimited funds, you might prefer the Metolius 5 Step Aider or the GradiStep for an etrier style aider. But the Fish Smart Aider will get you up any wall and have the advantage of being lighter than most aiders on the market. Also, if you are one of those people who doesn't like the urethane-coated aiders, this is the best etrier style aider to get.