Better control over the tone of each frequency, can make the mid-frequency warm and generous, the low-frequency is full and flexible, and the high-frequency is clear and not dry. Made of high-quality materials, strong, wear-resistant and durable. Ruby and sapphire double needles, Ruby for LP records and Sapphire for 78 rpm records. Structure: Polarity: When the needle tip is driven horizontally (left + right), the phase of the output voltage of the left channel (L) and the right channel (R) should be the same. Stylus: Ruby+Sapphire Output voltage: When the frequency F is 1kHz, when the vibration speed V of the sound groove in the L or R direction is 3.54CM/S or the vibration speed of the transverse sound groove is 5CM/S, the output voltage should be within +/- 4DB relative to the specified value (250MV) (ie: within the range of 200~300MV). Acupressure: When testing the tracking ability and electrical parameters of the cartridge, the acupressure should be measured within the range of 40 +/- 10MN. Note: Small items, please keep away from children to avoid being eaten by children. Colour: Black Material: Plastic Package Contents: 1 * Stylus Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.