You will love our PROFESSIONAL SERIES 20 ft Instrument Guitar Cables. Our cables have Oxygen-Free Copper for both the center conductor and the insulator shield. Most importantly, our cables have a VERY low Picofarad rating. Have you ever wondered why one guitar cable sounds better than another? They may look the same, but sound totally different? The main reason is the Picofarad rating. Most guitar cables have a high Picofarad rating. Some as high as 200 Picofarads per foot. A cable with a high Picofarad rating is much cheaper to make, and they will still work, but they will not sound as good. Our cables are rated at a SUPER LOW 36 Picofarads per foot (AWESOME). Most guitar cable manufactures don't even give you their rated Picofarads because they are so high. Why would you want to use a cheap cable with a hard plastic cover, no flexibility, and a high Picofarad rating? A good cable is just as important as a good guitar or amp.