Using Tips: 1. Ambient Light requirement for Operation: it?s better in dark place or at night. 2. When checking whether the egg to be incubated is fresh or not, just put the bigger side of egg to upside, turn on the led egg candler and aim at the top of bigger side. If the air chamber of it is very obvious, it means the egg has been stored for some time, at least more than 6 days, which is best not to choose it. The candling egg of small air chamber is fresh. 3. When candling the egg after it?s incubated for 4-13 days, vascular net can be seen. If it?s transparent without vascular net, it means the egg is not fertilized. It shall be removed once such egg is found. Specifications: Battery Type: Lithium Polymer Battery MAH: 2000mAh Charging Voltage: DC5V Operating Current: 330mA Luminous Flux: 120-130 lm Theory Charging Time: 3 hours. Note: This data is measured by laboratory for charging with a 5V/1A charger. The actual charging time can be different, depending on the charger. Theory Operating Time:6 hours. Note: This data is measured by laboratory. The actual operating time can be different, depending on the operating environment. Battery: 4 LEDs display the battery capacity. Each one represents 25% battery. When the 4 LEDs are all bright, it means a 100% charge status. ON/OFF switch faces upward at the front. The LED battery indicator lights are respectively 25% ,50%,75% and 100% from left to right.