Apply the Discount to Specific Products

Add a new field in the UI to specify which products can be subject to the coupon discount. For example, I have 3 types of widgets on my site, they are called Model 1, Model 2 and Model 3. Ideally, there would be a field listing all those products, and I would be able to select which one (or maybe use ctrl+click to select multiple) product's price would be recalculated if this coupon code was used.