Lotus Connect Store › Steel Tuning Fork, 658Hz Frequency (�5%) - Designed for Physics Experimentation - Chrome Plated Steel - Eisco Labs Steel Tuning Fork, 658Hz Frequency (�5%) - Designed for Physics Experimentation - Chrome Plated Steel - Eisco Labs $4.71 Single, 658Hz Tuning ForkMade of Steel658 Hz, +/-5% of stated frequencyDesigned for Physics ExperimentationPerfect for sound studyTuning fork to be used in science experiments. Tuning may be +/- 5% of stated frequency. Quantity: Add To Cart Added! Single, 658Hz Tuning ForkMade of Steel658 Hz, +/-5% of stated frequencyDesigned for Physics ExperimentationPerfect for sound studyTuning fork to be used in science experiments. Tuning may be +/- 5% of stated frequency.