The heat it classic with USB-C connection is compatible with Android smartphones and all iPhone 15 & 16 models (including Plus, Pro and Pro Max). The Apple MFi certification guarantees the best functionality and maximum security. On some smartphones from OnePlus, OPPO or VIVO, the "OTG" function has to be activated manually. Older Android smartphones with Micro-USB port must support the OTG standard and require an adapter. These Micro-USB smartphones are unfortunately not compatible: - Huawei P9 lite - Samsung Galaxy A5 - Samsung Galaxy A6 - Samsung Galaxy A7 - Samsung Galaxy A10 - Samsung Galaxy J5 - Samsung Galaxy J530 - Samsung Galaxy S5 neo - Samsung Galaxy S5 mini - Cubot Note S