The QA12 from Qualwave is a Between Series RF Adapter with Contact Resistance 2.5 mOhms(Outer), 4 mOhms(Center), Frequency DC to 50 GHz, Insertion Loss 0.08 dB, Mating Cycles 500 Cycles, Temperature -55 to 85 Degree C. More details for QA12 can be seen below.