When goods are combined in a single package to be sold as a unit there are a number of rules that apply. If the articles are essentially the same such as a "Plan-O-Gram in a Box" or wood frames, then one HTS code is correct. Sometimes the combinations can be designated as a primary HTS code such as Mirror Hanger Kits, which are essentially described by the plastic clip. 

In other cases, such as mirror sets where the sizes are assigned to different HTS codes or sidekicks where a range of articles are involved the list of included HTS codes must be presented to Customs to make an entry. In these situations the value of the goods must be apportioned to the HTS codes specified.