1.1[Hearing protection design]It is possible to switch between mode and normal mode, and it is suitable for children and teenagers. The 85db volume limit protects your child's hearing from loud sounds caused by incorrect operation of the device, making it a gentle headphone that protects your child's hearing. 2.2[Compatible models/ mode/normal mode] (1) Compatible with various devices with Bluetooth function and devices with 3.5mm AUX insertion port. (2) Can be used both wired and wirelessly, with a Φ3.5mm audio cable with 4 poles (with microphone), can be used as a wired headphone, and can voice chat with wired or wireless. (3) Kids mode is a mode with a limit of 85db for children aged 1-10, and normal mode is for people aged 10 and over. 3.3[Main specifications]Bluetooth version: 5.0; Charging time: DC 5V/1A; Use time: about 9 hours (LED light off); Standby: about 250 hours; Charging time: about 2 hours; Weight: about 160 grams; Working arrangement: about 10M; Working frequency: 2.402GHz-2.480GHz. 4.4[HI-FI High Sound Quality/Comfortable Wear]Equipped with 5th generation Bluetooth technology and 40mm driver unit, the sealed design provides excellent Hi-Fi sound quality. The clear and excellent sound quality allows you to not only study online, but also enjoy the deep and clear sound when listening to music or watching movies. In addition, it also has an ergonomic design. It weighs only 160g, so there is no feeling of pressure and it can be worn comfortably by children aged 3 and over.