Faced with the problem, maybe somebody had similar.
There is product in the price list he is one, unique, with its own code.
On the website there are 4 card product (women, women large, men, men large size), that is, to bind one card is not possible.
How can one trade offer to bind to 4 different products? That would at the same quantitative account was considered true (if you bought 1-well, the position of the card the women, it was subtracted from all cards)