Review on Mini USB Type C Fan Portable for Samsung Galaxy Note 8 Note9 A10 A9 Star A9s A8s A8+ A6s, Moto G7 G6 LG Stylo 4 Xiaomi Mi A2 Mi 8 Huawei P30 and More by John Hall

Cannot be used with a mobile phone case. After removing the case from the phone, you can use it. If used successfully, the battery will discharge by 1% (bad) in 5 minutes. You cannot use the keyboard/screen for typing when using the fan that covers 1/8 of the phone. It would be better if there was a longer "rod" to connect it to the phone so it doesn't get in the way.