The Stromberg Swell Portable Speaker is the best option if you are looking for a bluetooth speaker to take with you everywhere without worry, since it is IP54 certified, resistant to water and dust, and has a 1200Mah rechargeable battery that lasts up to 4 hours. The IP certifications that you have surely seen in other devices indicate the resistance to dust and humidity that it has. This is measured with tests that have to be adapted to international standards and guarantee the resistance and durability of Stromberg products. IP54 guarantees resistance against water jets for 10 minutes and against exposure to dust and other similar particles. This Stromberg Portable Speaker can be connected with another speaker of the same model or with the Stromberg Twin to create surround sound through its Stromberg Connect Bluetooth technology. State-of-the-art Stromberg Connect technology allows two audio playback devices to connect and output two different sound signals to create a stereo effect. The Stromberg Swell speaker also has subtle lights that give it an attractive touch that stands out at night. On the other hand, it has a real power of 15w RMS, a 1x3-inch diameter tweeter and auxiliary input. It includes a charger and, thanks to its measurements of 23cm high, 9cm deep and 9cm wide, it can be transported without major inconveniences.