35 x 45mm
Some colors naturally glow brighter than others. Colors such as yellow green, sky blue or blue green glow very brightly, while colors such as Red, Dark blue and purple do not glow as brightly.
Use LED light or sunlight. Sunlight quickly charges, while LED lights provide convenience in charging indoors or at night.
Note: Certain colors take longer to charge than others. Sunlight is an effective way to make sure that these colors get a good charge.