Sorry, I don't have one on the tip of my tongue, search for "Oatbox crystal set". If you are adventurous, roll your own "cats wisker" detector or just use a 1N34. I started with an oatmeal/cats wisker set and found them to be frustrating. Later I used a loopstick and 1N34. Purists might not like this approach, but they work better. You do need a strong nearby AM station.