If you would like to add item specifics to your eBay listings:
1. Navigate to the Administration > Inventory Settings > Custom Attributes
2. Click 'Create New Attribute'
3. Name the Attribute
4. Choose the type to be 'listing' and enter the item specific name
5. Choose the storefront to be 'eBay'
6. Click 'Save'. This attribute will now show up on the 'Custom Attributes' tab.
If you would like to add this attribute to your eBay listing template to show up every time you choose a category:
1. Click on the 'Listing Template' tab within inventory configuration.
2. Choose 'eBay' and choose a category.
3. Scroll down and choose 'add attribute' to add your new item specific attribute to your listing template based on the category you choose.
If you navigate to inventory management, click into the product details of a product and navigate to the listing attributes tab, you will now see your attribute when you choose your eBay category.