I don't know that Apple makes one. There are supposedly third-party products available;
here's one that claims to work with my Macbook Pro. I've never actually thought about it; I bought a laptop with a 15" screen precisely because I thought it would be big enough for 95 percent of what I do with a computer. With a full-size keyboard, a bluetooth mouse, and (of course) wireless network connections, I've never thought about needing a docking station at all. (And I used one with my previous laptop.) On the infrequent occasions when I need a bigger screen or two displays, I just plug one in.