Made of Aluminum alloy. The frequency and scale letter is stamped on each fork. Additional Info: Tuning fork, 256 hz. Package Size(L x W x H): 7.5 X 0.8 X 0.3 (IN) Categories: Tuning Forks, Aluminum HTS Code: 9209.91.8000 UNSPSC: 6.01048e+007 Country Of Origin: INDIA