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 iridescent. Multiple lights flash and emit light. Please use Panasonic BR435/2B or BR425/2B for the batteries. When night fishing, I have often experienced electric floats drifting offshore for various reasons, or the electric floats not lighting up due to poor contact and breaking down. Each time, I would buy an electric float for around 1000 yen or a float top for around 500 yen at a fishing tackle store. (/ _ ; ) I really disliked repeating this, so I decided to make them by hand for myself and for others who have had the same experience and feel the same way. I would be happy if you could try it at least once. Thank you m(_ _)m Also, please refrain from purchasing if you are concerned about it being handmade.