Set quantity or packaging.
Limitations of minimum and maximum quantity of purchased product.
Furthermore, the possibility of buying only a quantity that is a multiple of a certain number. Alternatively, you can set up specific choices for a variety of products, ie different packages.
Metric Editing - Default Value and Multiple Count
You can define a default value due to system update v. 17 in the administration. For the customer, everything is automatically counted to the nearest possible value that can be ordered.