The bluetooth headphone is a great tool for online learning and enjoying music. It have high-fidelity sound quality, which is important for enjoying music and providing an aural feast for you or your childfeatures support tf card playback, support hands-free calls it can be used for talking up to 6 hours with a charge of 2 hours three connection methods tf card, bluetooth, and wire, can meet your different requirements foldable and length adjustable support volume adjustment and song switching perfect for online courses, classes, movies, etc. Specifications material abs colour green package size 17 x 11 x 7 cm bluetooth version 5.0 bluetooth transmission distance 10m audio cable plug type 3.5mm audio cable is not include tf card support not included bluetooth frequency 2.401ghz - 2.480ghz fn frequency 87.5-108mhz battery type lithium battery battery capacity 150 mah package content 1 x bluetooth headphones 1 x charging cable 1 x user manual please note 1. Due to manual measurement, there might be a tolerance in the product size. 2. Due to the light and screen setting difference, the item's color may be slightly different from the pictures.