The Herb Case is a special item in Resident Evil Outbreak. It is Cindy Lennox's personal item, and is thus present in her inventory at the beginning of each campaign. Like all personal items, it cannot be discarded.
The Herb Case lets Cindy store herbs she finds around Raccoon City more efficiently than most characters. It has three separate compartments, with each compartment being able to store up to three herbs of the same type. It also has a smaller fourth compartment for carrying mixed herbs.
To transfer a herb from Cindy's inventory to the Herb Case, simply combine the item with the case. Any mixed herb in her inventory cannot be transferred inside the case; however, you can mix any two herbs in the case, creating a mixed herb that will automatically transfer to the fourth compartment.
Cindy can use the AID option to use a stored herb on a nearby character. Using AID while shouldering an injured partner also works.
At the beginning of each mission, Cindy's Herb Case contains two Green Herbs, one Red Herb, and one Blue Herb.