The RMS (root mean square) power is expressed in watts and describes the actual intensity of the speaker. A speaker up to 10W is recommended for indoor use, while 20W and above is suitable for outdoor use.
For Bag & Bicycle: Small, lightweight speakers with an integrated cord, ring, or carabiner. They can be easily hung on a school bag, backpack, or bicycle handlebar.
Hands-Free: Ability to connect to a mobile phone and use as a hands-free device thanks to the built-in microphone.