Fangrui Product Details Use It For:1.instant Relaxation2. Deeper Meditation3.improved Sleepimprinting Frequencies On To Objects How To Use:– Plug The Device Into A Wall Socket, Laptop Or Power Bank Using The Provided Usb-c Power Cable.– Connect Some Earphones To The Device Or Connect The Device To A Speaker Using An Aux Cable.– Type In The Desired Frequency Using The Touch Pad On The Device. – Press “ok”. Specifications:working Voltage: Dc 5v (dc 4-15v)working Current: 9-14mapower Interface: Type-c(support Type-c To Type-c Power Supply)default Frequency: 7.83hzadjustment Range: 0.01hz~30000hz Pure Sine Wavesignal Voltage Amplitude: 3vwith 3.5mm Audio Outputwith Acrylic Shellsize: 155*105*26mm(with Shell)weight: 300g(with Shell) Product List:1pc * Healflux Custom Frequency Generator V2 (with Acrylic Shell)1pc * Usb Cable