Adjustable weights for tunnig fork

The plastic body with the inside dimensions of the tuning arm and the fastening screw serves to reduce the frequency given by the tuner. The weights is placed in the upper half of the tuning arm and slows down the oscillation of the arm by its weight, so there is a measurable difference from the original frequency without the load.
Fatigue or excessive tightening of the fastening bolt causes the bulk to break and degrade