The 3.5/SMP-JK from Talent Microwave Inc is a Between Series RF Adapter with Frequency DC to 26.5 GHz, Insertion Loss 0.25 dB, Insulation Resistance 5000 MOhms, Temperature -55 to 165 Degree C, Voltage Rating 750 V. More details for 3.5/SMP-JK can be seen below.