This is about the size of a golf ball, and is made from a robust plastic. It is filled with a fluid so that the part that gives you the answer is floating free inside.
Think of your question, give the ball a shake, and turn it so that the clear side is uppermost, the little floating answer shape floats up to the see-thro panel and you read off your answer.
I like this simple little toy as is also then can sort out family disputes "do we go to the cinema" "should so-and-so tidy her room now" etc - and if the child shakes it to get the answer they feel the answer if fair! - go on get it, it's great fun and also brilliant as a party bag gift.