With TWS technology, you can link two E5 together, and play the left and right music channels with these two speakers. It will be like a set of wonderfully sounded 2.0 stereo speakers, except they are portable.The waterproof level of HAVIT E5 is IPX7, which means it can be immersed into 1-meter-depth of water for 30 minutes. Take it to a short swim, or listen to the music while taking shower.