Gray Flat Ribbon Cable (FRC), 40 Wires, 1 Meter

At 40 conductors, this is the widest common ribbon cable size, historically associated with IDE hard drive cables and still useful today for wide GPIO breakout connections, such as wiring a Raspberry Pi's full 40-pin header out to a breadboard adapter or custom interface board. Having the full conductor count in one cable avoids having to run multiple narrower ribbon cables side by side to cover the same number of signal lines, keeping a wide parallel bus connection tidy and easy to route through a single IDC connector.