Are you planning to define the multiples of quantities to the products? Some products come in a bunch of 6, 12, etc. You can set easily multiples of quantity using this module. Suppose you want to set multiples of quantity is 5, it will default the value of the product in the sales. If you put manual quantity (manually = 8)of the product so it will automatically take higher No of quantity(higher = 10). You can increase or decrease the number of products relative to default quantity(default is 5) in the sale order/quotation.