China CNC 6040 Limit switches

I've built a number of machines and decided the cheapest way to get all the parts (my time is not free) for a dedicated engraving platform was to buy a Chinese 6040 4 axis system. It works well and I have it all working with LinuxCNC. My only issue is that I didn't get the one with the limit switches and now I kinda regret that. But I should be able to add them easy enough.

The breakout board has a header for them and the back on the control box has the cutouts. I have no idea what type of connector it uses though, any idea?