Baby interact with the sounds,encourage curiosity Features Size:38.5x 14.2 inch(98X36 CM) Batteries Powered: 3*AA Battery(Not Included) Material:Plastic + Nylon+ Non-woven fabrics 1. instructions? ~~ There are detailed instructions for each package/ reading the instructions for use on the product page. 2. Slip? ~~ The upgraded piano mat is made of non-slip material that prevents the pad from sliding. If you put it on the carpet, the anti-slip effect is better 3. Volume too high? ~~ The volume is adjustable and the lowest sound is equivalent to the decibel level of whispering. 4. not working? ~~ Please install 3 x 1.5V AA batteries and turn on the power switch on top of the piano speaker. You need to touch the red switch on the piano pad again, as it will automatically turn off after 2 minutes of no play. 1) Please don't use different types of batteries at the same time or mix old and new batteries. 2) If not used for a long time, please remove the batteries from the music pad.