The BLADE bone conduction speaker isn’t your average audio source. Using bone-conduction technology, this super-thin gadget can actually turn anything into a speaker! Simply place it on anything hollow—like a helmet or coffee mug—and it turns it into an audio-emitting powerhouse. You can even attach it to an instrument if you want to play music a bit louder. In fact, with a volume range up to 115 decibels, the BLADE speaker is around five times as loud as your average smartphone or tablet. About the same size as a credit card, this portable speaker weighs only 35 grams and is as thick as a piece of cardboard. Compatible with Bluetooth gadgets, this speaker pairs with another BLADE to produce true omnidirectional stereo sound. Finally, its 4,000 mAh battery lasts for up to four hours. And it charges via its high-speed USB-C port to power it up in fewer than 30 minutes.