The LED indicator lights on the handle of the massage gun indicate the battery power remaining on the gun. the four lights represent how many quarters of battery are left, for example, 3 lights indicate that 3 quarters or 75% of battery remain, and 1 light means that 25% of battery remains.

If the last LED is on and starts flashing, it means that only 10% of the battery remains and you should begin charging it.

When charging, the light will flash blue, and when the become a solid blue, it means that the battery is fully charged.