These premium jumper wires are 20cm long and come in a ‘strip’ of 40 (4 pieces of each of ten rainbow colors). They have 0.1″ female header contacts on both end and fit cleanly next to each other on standard-pitch 0.1″ (2.54mm) header.
The best part is they come in a 40-pin ribbon cable. You can always pull the ribbon wires off to make individual jumpers, or keep them together to make neatly organized wire harnesses.
For best results, when plugging these in a line, have the sides with the ‘silver latch bit’ sticking out since that side is a tiny bit wider than 0.1″