Bottle-light / Bottle holder

We found in the same distance, with the same flashlights and the same volume of water, air and solid (ice), that the illumination of three media is in the order of water > air > solid.
Bottle-light combines a water bottle holder and an LED lamp. Its advantages include: (1) you do not need to carry an extra light since the bottle is also a lamp, and (2) light goes through water, appearing in the shape of a bottle, which is like a lighting box giving out more extensive light instead of point-like light.
Bottle-light has four use scenarios, changing modes of illumination depending on your preference. It could be fixed on the handle or seat of your bicycle to increase nighttime safety.