For Ranger School, this is an optional item and you are allowed to bring 60 pcs of non-energy / caffeine free gum. I recommend you bring gum that isn't sugar free. Also, when I went we were only allowed to bring sixty pieces, but I brought way more than that and was just smart during the layout.
For Sapper Leader Course, this is an optional item and there is no limit to what you are allowed to bring.
These 60 pieces come in a 6 mil plastic bag that fits perfect in your cargo pocket. The durable 6 mil plastic bag will keep you gum safe and dry while your on a patrol. It comes in three flavors Apple, Grape, and Watermelon, so that you won't get bored with one flavor. They are individually wrapped so that you can share with you battle buddies.