All enclosure rearpanes are made for Neutrik NC3 MAAH (male XLR) and NC3 FAAH (female XLR).
These connectors are very reliable, economically priced and widely used in the pro audio business.

I sell these connectors for 0,84€+VAT including black screws.

IMPORTANT NOTICE:
If you want to use different XLRs keep in mind that they might need different cutouts. (center hole and for the screw hole positions)
If you need any other cutout you have to send me the pdf Datasheet of the Connectors you want to use