A Cooper bowl helps the right-hand shape of piano playing as well as the strength of the fingers. 

The weight of the copper bowl help to strengthen the grip. The bowl's round shape supports the arch of the palm for piano playing. This particular bowl is designed for preventing slippery with the indented bands in side. 

With Joy Song Piano Icon study, various ways to produce sound can be learned. 

* Small size for 5~8years old Large size for 8 years old ~ adult depending on the size of the hand

* The Bronze Bowl is handmade, so there may be a ± error in the weight I suggested.