LED Therapy: Intro to Hardware Hacking Using the Neutrogena Light Therapy Mask
My girlfriend's acne mask uses this to work and only contains 30 charges. After the uses she has to buy a completely new one of these every time : r/assholedesign
Amazon.com : Unlimited Light Therapy Acne Mask Activator, Reusable Device with Unrestricted Count (Rechargeable) by Liihot : Health & Household