final --> for primitives --> value can't change. for non-primitives --> you can't change the reference and point it to another object. Note : It is different from immutability.
Hands down, the Bluetooth speaker with the longest battery life is the Fugoo. It offers up to 40 hours of battery life, nearly twice the battery life of other leading Bluetooth speakers in this category. Given how long its battery lasts, you might even forget that the Fugoo needs to be plugged in to charge.
The Good The JBL Flip 3 is a highly portable Bluetooth speaker that's splashproof and designed to be used horizontally or vertically. It sounds very good and plays very loud for its size, can act as a speakerphone and offers improved battery life at up to 10 hours.