Noctua LNA Resistance Values Resistance values for Noctua low noise adapters (LNA) Classic Black LNA 51Ω Classic Blue ULNA 81Ω NA-RC6 81Ω NA-RC7 51Ω NA-RC8 150Ω NA-RC9 100Ω NA-RC10 51Ω NA-RC11 98Ω NA-RC12 150Ω NA-SRC7 is a set of 3 NA-RC7 51 Ohm 4-wire adapters