Here you can assign weight specifications to products. This Information page can be found under 

Log in to your admin panel and go to System> Localization> Weight class. Obviously, all weight classes are already on the list, if you need can add more!

Let’s take a tour by exploring the setup of the weight class.

These weight classes can be used to manage customer orders' weight. Each weight class can be individually disabled, by editing them. The Weight class can be deleted as well.

Note:  The weight class information should be created before products are added. 

You can edit the weight class by clicking the edit pencil button.

you can choose to  "delete" the Weight Class on the top left corner and click the + button to add new.
Note: You cannot delete if the weight class is already used for the order. Once you delete the order then can delete the weight class as well

 To insert a new weight class  click + Button, the following screen will be displayed

Weight title: Type name of the weight measurement (i.e. Kilogram)
Weight Unit:  Enter the units of measurement (i.e. kg)
Value: Enter the value - this option is calculating the default value so set up one default value (There are 1000 g in 1 kg, so the value of g would be set to 1000)

Finally, check that all the mandatory (*) are filled, and pressing the 'Save' button in the upper right corner will save the information.

 Then how to use this weight class -- catalog --> product --> Data tab --> give the weight class

Let's take a look at how the weight class will display from the front end of your store

In Website view

In Mobile view

Congrats!!! Now your product weight class is enabled to the public, Which will help your customers make an informed decision with their purchase.