Review on 💡 High-Quality 10 Pairs of 12V 5A DC Power Pigtail Cable with 2.1mm x 5.5 mm Male & Female Connectors - Ideal for CCTV Security Camera and Lighting Power Adapter by Daryl Barton

I bought 3 of these packs, from an open pack 7 out of 10 connectors have some sort of internal break on the negative side. Slightly pressing (less than 15*) or rotating the base of the connector where the wire is connected will cause the negative connection to open somewhere (tested by placing a multimeter on the negative wire and the outer metal part of the housing, while the multimeter is in continuity mode ). One of the seven had no connection even when straight and stretched. This makes it impossible to use in applications where the cable can be moved or even bent at all. However, 5 of the 5 jacks I've used so far work fine. Sockets sometimes have an open gap when connected. TL; DR: poor quality control, more than half of the connectors in a package were defective.