The Sony SRS-XB13 Portable Bluetooth Speaker in Black offers Bluetooth 4.2 connectivity, up to 16 hours of battery life, and features Extra Bass for enhanced sound quality. It is waterproof and dustproof (IP67), with a rechargeable battery and a mono speaker unit. You can pair up to 2 speakers and use the Sony Music Center app for control. The speaker weighs 253g and measures 74.5mm in width, 74.5mm in depth, and 94.5mm in height.
eBay