Thank you for viewing my product m(_ _)m Not only the lithium battery BR435/2B, but also the shorter size BR425/2B can be used. The light color of this product is red. Please use Panasonic BR435/2B or BR425/2B for the batteries. When night fishing, for various reasons, my electric float has often drifted far out to sea or malfunctioned due to poor contact, causing the light to go out. Each time, I would buy a new electric float for around 1000 yen or a float tip for around 500 yen at a fishing tackle store. (/ _ ; ) I really disliked this repetition, so for myself and for others who have had the same experience and feelings, I decided to make them by hand. I would be happy if you would give it a try. Thank you m(_ _)m Also, as these are handmade, please refrain from purchasing if you are concerned.