Features: 1.This 61?key hand?rolled piano has 128 tones and rhythms that can be changed, as well as sustain, vibrato and drum sound effects. The sounds of all kinds of instruments you want can be played. 2.This hand?rolled piano can simulate piano sound, and has high?fidelity stereo speakers, which can support Bluetooth. 3.This electronic piano can be wirelessly connected with mobile phone software, such as the bubble piano software,as well as the phone. 4.This hand?rolled piano can be connected to a microphone, the MIDI function of speakers or other power amplifier devices and computers, tablets, mobile phones and other devices. 5.The built?in lithium battery has a protection function. When the voltage is lower than 2.9V, the machine cannot be turned on or automatically shuts down after it is turned off. specification:Item Type: 61-Key Hand-Rolled Electronic Piano Material: ABS+Silicone+Electronic Components Power Supply Type: USB External Power Supply/Lithium Battery Lithium Battery Capacity: 1000mAh (with Built-in Battery) PackageList: 1 x 61-Key Hand-Rolled Piano 1 x Sustain Pedal 1 x USB Cable 1 x English User Manual Note1.It is a red LED indicator during charging, and a green LED indicator when fully charged. 2.When the voltage is lower than 2.9V, the hand?wind piano cannot be turned on or will automatically shut down after it is turned on. The purpose is to protect the lithium battery. 3.Therefore, when the power is too low, it needs to be charged in time.