What are the nike golf balls with the 4?

Ok I found a nike golf ball and I loved it. It had a 4 under the Nike Swoosh and I can't seem to find them online to buy. What do I search to find them?What are the nike golf balls with the 4?All golf balls are numbered for identification purposes, usually 1, 2, 3, or 4. When purchased by the dozen they usually come with a sleeve of each number. Any golf shop or online retailer that sells Nike balls should have them.