When you want to buy something but you don't know how to get what you want you call around to the vendors. They tell you about the products they're representi

When you want to buy something but you don't know how to get what you want you call around to the vendors. They tell you about the products they're representing, and you figure out what you like best. When you put out your solicitation you confine it to products that narrowly match the description of the actual product you want (without naming it, that would be sole source which is different). This is achieved by naming features that are patented or otherwise IP protected, therefore excluding competing products. Sometimes if you're sloppy you can get stuck with a competing product and then you've got a problem on your hands. If you're not worried about price this is a great way to get what you want. But it can mean a 20%+ cost premium, depending on the niche and how aggressive the salesman is.