The phrase "blind packs" refers to a type of product packaging where you cannot see what is inside. It is like a surprise because you do not know what you will get until you open it.
Sentences with «blind packs»
Seeing as they're sold in blind packs of two for around five bucks it's entirely possible you'll get a lot of doubles much like you would if you collected baseball cards. (cogconnected.com)
But what's not cool is having to purchase those discs in blind packs of two, never knowing what you were going to get. (kotaku.com)
Instead of buying discs in blind packs like before, they are now available in themed packs of four. (egmnow.com)