Let me share some information about the availability of the unit of measure (U/M) in QuickBooks, LAG1.

The single and multiple units of measure for items are only available to the following QuickBooks products and editions:

• QuickBooks Accountant
• QuickBooks Premier Contractor
• QuickBooks Premier Manufacturing & Wholesale
• QuickBooks Enterprise Solutions
• QuickBooks Enterprise Solutions: Contractor
• QuickBooks Enterprise Solutions: Manufacturing & Wholesale
• QuickBooks Enterprise Solutions: Nonprofit
• QuickBooks Enterprise Solutions: Professional Services

Based on the screenshot you've provided, it's possible you're using other Industry Type in your QuickBooks Desktop Enterprise. You'll want to use the U/M feature, it would be best to contact your accountant first if you're planning to switch to a different Industry type.

To learn more about the unit of measure, just check out this article: Use single and multiple units of measure for items.

I'm just a click away if you need a hand with managing your inventory items or any QuickBooks related. I'll be here to help.