Sell an item with multiple unit

Sell an item with multiple unit

Hello Sir/Madam
I am new to Zakya. I am planning to subscribe to zakya
But i have just one problem.
How can i sell an item with multiple unit.
Like for example.
I have an item "Pepsi". 1 box contains 24 bottles.
So on the POS i wanted to sell both in bottle and also in BOX.
I don't want to create composite item because it is the same item and also its difficult to maintain the stock

PLEASE HELP