What is this called?

[blueskull]

What is this connector called? The one with one pin plugged so that you can not plug it in the wrong direction.

Where can I buy housings for this connector? Or where can I buy pin "plugs" for a 2.0mm Milli-Grid connector?
I do not want to pay extra shipping cost, so it will be better if I can get them from Mouser.
As a reference, the connector housing I'm using is Mouser 51110-1050. I want one with a corner hold plugged, or a plug that I can permanently plug into its corner hole.
The connector in this picture has 2.54mm pitch, I need 2.0mm pitch.
Thanks in advance for all inputs.

[ataradov]

Searching for "key plug for IDC sockets" leads to this - http://www.toby.co.uk/content/catalogue/products.aspx?series=KP-01

There is not too many hits on this kind of stuff.

But search result is interesting on its own. It looks like plugging any number of pins is an option from many manufacturers, subject MOQ, of course. Nut much information on standalone plugs, although I've seen then in actual products, so they can't be that rare.

[David_AVD]

For what it's worth, I buy these on AliExpress for about AUD $16 per 200 shells.

[rdl]

You should be able to recreate that connector using Molex SL series parts. Mouser sells them. You'd want a dual row 10 pin housing, the crimp on connectors to fit, and a key plug. AMP/TE has similar connectors.