As D-type pins are 1-mm diameter, I'd expect any D-type female connector to work with the negative terminal. Here's one from Molex, but obviously there are very many manufacturers and endless styles (crimp, solder, etc): [![enter image description here][1]][1] Molex [web site](https://www.molex.com/en-us/products/part-detail-pdf/1731120021) [1]: https://i.sstatic.net/VCvs5S8t.png [2]: https://i.sstatic.net/gi0NMbIz.png