It's related to selling items in groups. Set the product price at $1 and minimum units to 5, every order will be $5 (ie 5 x $1). The unit mix is asking if the 5 units can be mixed eg 2 red, 3 green.
I can't be any further help as I'm only using single items and no attributes.
Search the forums though, there are plenty of relevant threads with better examples and explanations.
Thanks Moderator. I thought I did have more than enough detail, but was getting no answers or responses. So I simplied it and got an answer.
I spent quite a bit of time searchin the forums but never did find any answers
I'm trying to find a way to set minimum quantities but allow a customer to buy less than an items minimum, but reach the minimum number from buying several items.
I still have not found a way to do that.
I am thinking of trying to find a way to just require a minimum dollar amount on the order ot it adds a charge of say $5.