It's the top part of the connector, it is what pushes down on the top part of the ribbon cable and clips in.
All the IDC connectors I've seen have semicircular indents on that portion of the connector which wrap around the wires. That looks like it might be some kind of tape you have to peel the backing off of. Or perhaps it's just some cardboard which is there to prevent the connector from seating in place during transit? I think I got some connectors once with something like that.
And they're $4 each
Is that expensive to you?
When I need to make or get 50 of these cables manufactured and I'm working on a shoestring budget? Yes.

Anyway, thanks for the help guys. I determined that it was cheaper and easier to just get the cables manufactured.
This was what I was planning to do originally on one end of the cable:

But for what it would have cost me for the 300' of ribbon cable and IDC connectors (the second rainbow cable was another $100 on top of that), I was able to get 375' of cable with crimp connectors on each end plus housings, so I can have the cable terminate with the proper connections instead of doing a half-assed job. I was only considering the IDC connectors because the other option would have been crimping 1600 connectors by hand myself, and aside from having no interest in doing that, I was also pressed for time.
This is what the cable is for by the way. It's a 7.5' long cable which extends all the switch, strobe, and vibration motor cables from the gun to the backpack:
http://www.mightymicrocontroller.com/kits/proton-pack/
In the videos, the kit is installed in the gun, but many people wanted to be able to install it in the backpack so as to have more room in the gun for tip extension mechanisms and speakers and the like.