The K2 Wilson Pickup consists of two single piezo elements gathered to a Switchcraft 121 extension jack. This pickup is suitable for all double basses and provides almost the same sound assets as the original K4 Wilson Pickup with 4 elements such as body and warmth natural sound with no feeding back at any level. Positioned in the bridge 18 mm below the strings in between the E/A and D/G the sound level can be balanced by slightly rotating the pickup in its mount. K2 is the cost saving alternative to the K4 without compromising the quality of your sound. Special mounting tools and mounting bracket are included with each set of K2 pickups.