The ESI 01 4K2 1x from Exxelia Technologies is a Space Qualified Inductor with Inductance 4.20 µH(No Load), Inductance Tolerance ± 20%, DCR 26 mOhms, Saturation Current 1.70 A(Rated), Temperature Operating Range -55 to 125 Degree C. Tags: Surface Mount. More details for ESI 01 4K2 1x can be seen below.