Product Description Please note the size: 2.36 x 2.36 x 2.36 (inch) Recommended for ages 5 & up, children should be used under adult supervision. It is a puzzle that will entertain and challenge all ages When assembling requires careful observation and thinking, analyze its internal structure.Our mind puzzle help to exercise brain, develop intelligence, improve problem-solving ability, and also relieve pressure Tips: paper instructions and video link QR code is prepared, but in order to make it challenging and fun, we suggest you try your best to unlock this wooden ball puzzle without instruction