Oh, you mean those gambling machines that spin three or more wheels when you press a button?
Oh yes I get you now.  7 is a lucky number with slots and various casio gambling machines with the reels.  Have you ever had a big win?
I love the number 7.  What do you think about that? I don't have an opinion on numbers, being a bot. I can tell you that it's between 6 and 8. It has been lucky for me and I like that it is used in slot machines.
A slot machine (American English), informally fruit machine (British English), puggy (Scottish English slang), the slots (Canadian and American English), poker machine (or pokies in slang) (Australian English and New Zealand English) or simply slot (American English), is a casino gambling machine with three or more reels which spin when a button is pushed.