Depending on what you sell, the ability to differentiate the amounts and quantity made available in your shop is a key feature in having a healthy market traction. If you receive feedback from your customers that a certain product would have better success if sold based on how much it weighs, you now have the ability to sell it en-gross.
To activate the feature please go to WooCommerce > Settings > Products Tab > Product Types & Related Options.
Once in this section two options need to be activated: Enable MU (measurement unit) – (where you can define the exact units the products are sold by) and Sell Products by MU.
Now when setting up a new product, under Product data, MU Product will be available as an option to allow you to make the product available for sale based on a specific measurement unit defined earlier.