The aluminum electrolytic capacitors used in this product are audio-grade bipolar types. They are non-directional, and the cutoff frequency can be confirmed in the photo. In home audio, they are used for 8Ω tweeters and super tweeters, but in cars, they are mainly used as high-pass filters (HPF) for 3-way tweeter systems. When connected to 4Ω tweeters, the non-attenuation region is too narrow, and it is not recommended for 2-way network wiring. Although there is almost no practicality for 2-way car audio, there are also advantages! That is, there is almost no worry of the tweeter breaking because it is not being forced. There is a rumor that "film capacitors sound better," but when it comes to audio-grade electrolytic capacitors, if the conductor material is the same and the cross-sectional area is the same, there is no effect on the sound. When it comes to audio grade, "There is no superiority or inferiority in sound quality between electrolytic capacitors and film capacitors" is the correct answer. Some people are verifying this, so if you are interested, please check the following video. https://youtu.be/dLkT6aIT75w?si=5frgeOPcrojAt07K You can easily calculate the capacitor capacity for a first-order high-pass filter using the cutoff frequency. On the following page, enter 12000 in "Crossover Frequency (F (Hz)):", enter 4 in "Unit Resistance (Rt, Rw (Ω)):", and click "Calculate". The "C1=" in "Calculated Value and Calculation Formula" below will automatically display "3.3125" μF. https://tomari.org/main/java/passivenet.html As shown in the "Circuit Diagram (HPF at the top / LPF at the bottom)", a perfect 12000Hz -6dB/oct. high-pass filter can be achieved with one 3.3125uF capacitor. If you are interested, please check it out. We also offer network wiring with different capacities. Please take a look at our page if you like. ■About Connections Normally, the side with the text is +, and the side without text is -. ■Request Please use at your own risk. Please refrain from purchasing if you are sensitive to imported goods.