For products that are very similar, you may use product attributes to further differentiate it, like colour, size or features.
To create a product attribute you will need a name to define each feature.
Then for each attribute you define the options that are available. For example the attribute size comes in small, medium and large.
Step to create a product attribute
Select the Attributes tab from the product and click on the Create New Attribute button.
Key in the name of the attribute. If selection is a mandatory field for customers, check the 'Required' option. Click on 'Next'.
Enter the option sub-SKU and name. Enter the weight difference if it affect the shipping weight. Press Insert.
If the option changes the price of the product, key in the price difference and click Update Option.