by Zefferin LLamas
Chest binders are compression undergarments used to flatten the chest. Many different types of folks use binders, including (but not limited to) transmasculine and gender-nonconforming people. Binders may help smooth the way for trans teens, but it is important to know how to measure these garments to find the right fit for you.
Check out this useful sizing video from gc2b for more information.
Also, check out this great binding guide: Binding 101: Tips to Bind Your Chest Safely from Point 5cc, for more general information about binding.