The 1.85/3.5-JK from Talent Microwave Inc is a Between Series RF Adapter with Frequency DC to 33 GHz, Insertion Loss 0.28 dB, Insulation Resistance 5000 MOhms, Temperature -55 to 165 Degree C, Voltage Rating 1000 V. More details for 1.85/3.5-JK can be seen below.