“Perfectly small and discreet, i.e. volume not much larger than the tree triple-A batteries that it contains, and has an integrated on/off switch. This means that it can be feasibly integrated into wearables without worry and regulatory issues presented by LiPo batteries. I mounted mine with velcro tabs because the side with the switch is opposite to the cover that needs to be taken off to access the batteries for recharging or replacement.”
“Perfect for my audio project, thanks to the built-in on/off switch I can interrupt tunes if I don't want to listen to one fully and play a different one.”