Hi there, mohilbeautylimit.
The Unit of Measure feature helps to manage inventory items with different units. It is available in our QuickBooks Desktop version. In QuickBooks Online, you can use the description field to show the item details (for example 1 gal). Please click on this link to see the steps on how to set up inventory items.
We have been sending feedback to our product engineers about adding this feature in our future updates. Please allow us some more time to review this request.
Stay tuned for more new product features by following our QuickBooks Blogs.
We are ready to answer your other questions. Please post them below.