The WELCH type tuning fork are intended for student use and for general experiment work. WELCH type tuning fork often selected for student use and preferred for laboratories standards and for applications requiring longer duration of vibrations. Set of 8 tuning fork marked with its number of vibrations. 256C 288D 320E 341F 384G 426A 480B 512C Large Tuning Forks. The accuracy of fork is adjusted considerable care by skilled technicians. Supplied in velvet box