These are 20 cm long jumper wires terminated as Female to Female. Multiple jumpers can be connected next to one another on a 0.1" header. Comes in one pack of 40 jumpers (colors shown). Each group of jumpers are connected to each other and can either be pulled apart in any quantity (from 1-40, of course) or kept whole based on you needs. These jumper wires can be used for pretty much everything! They work great with breadboards, Arduinos, and really any 0.1" pitch prototyping board.