What is the square wave button next to the AC?

[StKylie]

The square wave button next to the AC is the defogging and heating function button. Here are the relevant introductions: Introduction 1: There are generally two defogging buttons in a car, one is the front windshield defogging button, usually marked with a fan shape and a wave line, and the other is the rear windshield defogging button, usually marked with a square and a wave line. Introduction 2: The front windshield defogging relies on the air conditioning system, with dedicated air vents located near the front windshield on the center console. The rear windshield defogging mainly uses electric heating wires. After turning on the rear windshield defogging switch, the heating wires will generate heat, thereby achieving the purpose of helping to defog.