1. Free SD card with the mantra.2. 3.7 V 1200 mAh rechargeable batteries. Charging in 5 hours then can be used for 2-3 hours while open the mantra sounds or 35 hours if open only the light.3. Dual power; can be charged with both batteries or home electricity charging. (not include an adapter in the set)4. Press the button on the censer to control the mantra sound. Press the middle one to pause and resume. Press the left or right one to play backward / toward
moreover, long press to decrease/increase the volume.