HS4778-102 REV J is a type of PCB header from TE Connectivity. It is 2.54 mm pitch, dual-row, right angle, and has a 2×20 pin configuration. It is made of tin-plated Phosphor Bronze and has 22-28 AWG wire size. It features an insulation displacement contact (IDC) termination and is designed for applications such as wire-to-board, cable-to-board, and wire wrapping. The overall length is 7.03 mm, the number of rows is 2 and the number of pins is 20. It is also RoHS compliant.