Dual drivers and low-frequency radiator provide crystal clear stereo sound and rich powerful bass. No distortion, no noise and no delay. The maximum sound can be up to 20 watts (Dual 10 watts), loud enough to cover a big room. In TWS mode, two speakers can even provide total 40 watts super big sound. In Bluetooth mode, TWS (True Wireless Stereo) function can pair any two Zoweetek speakers (ZW-BSP04) via Bluetooth, then dual-channels stereo audio can be played in sync on both speakers. One speaker plays left-channel sound and another one plays right-channel sound. Shockproof, dust-proof and IPX5 waterproof. Water splash, rain, dust and impact won't effect this speaker. Equipped with a hand rope, this speaker is portable. You can take it to beach, pool, forest and etc..