2.54mm Pitch Screw Terminal Block 2 Pole (10 Pack) QSU

These are nice in that they can plug directly into a standard breadboard, but that means that they have to be small. That tiny size makes them more difficult to work with. But that's to be expected--that's the size they have to be.However, they seemed a little on the loose side in my breadboard. It seemed like they worked "ok" but were not quite as solid as I would have liked. In the end, I only used them briefly.