I'm in need of a 2x13 0.1" pitch female header with tall pins - tall enough that they can pass through one PCB and still be long enough to reliably mate with another female header. This is a familiar problem; I've been here before. Many times. I have bought headers from different suppliers and different manufacturers, but they are always the wrong type - unusable due to having flat, flimsy, rectangular pins, rather than the square shape required to make good contact. I have dozens of them. I have spent hours troubleshooting intermittent failures, only to find that, ah yes, those damn headers don't work properly. If anyone can help me find a source for good quality female stacking headers with square pins I'll give you the ones I have as a reward.