Sears has been doing the 'Amazon thing' for a while now. They will list items from any seller on sears.com. Unlike Amazon, they don't stand behind the sale. (Or, I should say, "even less than Amazon").
Much like on Amazon, sellers take advantage of this by listing a wide array of items that they don't actually stock. When they get an order, they have the actual supplier drop-ship the part, profiting on the difference in price and excess shipping fees.
This might seem like harmless arbitrage, but it falls apart when there is a problem. They'll cancel the order if they can't find the part or won't make enough money because the real supplier raised prices. They'll delay shipping if they find a cheaper supplier. (You pay for extra for two day shipping, and they mail it out a week later with two day shipping..)
And, like the case here, they don't really know what they are selling. A computer program cut and pasted the description from some other website. They expect the buyer to check if it's the right part number for item they want, or to guess if it's a single wrench or a whole set. Or a case of 12 vs a single item that was previously boxed with 11 others.