Has anyone used this type of FC crimp connector? What is the model number?

[Crsus]

From the picture, it appears to be 50-pin and 44-pin, with a pitch of 2.0mm，The other parameters can only be seen from the picture。

[tooki]

Looks like a normal 2mm IDC connector. Is there some specific aspect you are looking for??

[squadchannel]

what wrote in here?

[Psi]

If you're looking at the white no-pin slots as if they are part of the connector, they are not.
They are just inserted bits of pin shaped plastic to create any type of keyed arrangement you want.

[Crsus]

Look for a matching plug

[squadchannel]

crsus, what does the red circle area say?

[RoGeorge]

I don't know the part number, but it looks the same as the IDE (for hard-disk, CD-ROM, DVD unit, etc.) ribbon connector used in desktops, before they were replaced by SATA.  Except those were 40pins, not 44.  Same type of connector used for SCSI ribbons, except SCSI were 50pins.  They are often listed as 'IDC connector'.  Search for '44 pins IDC ribbon connector'. 

I see now the 3M name is molded-on socket:
https://multimedia.3m.com/mws/media/446388O/3m-molded-on-cable-assemblies-guide-3m-us.pdf?fn=Molded%20On%20Cbl%20Assm%20dynamic.pdf

[squadchannel]

Of course, you can use any 2mm IDC.

what the OP needs probably the perfect matched connector.
this connector does not look like a typical IDC. There is something like "hook" shape on the end.

hard to see image says HDD.
2.5" IDE requires 50 pins when use with the master slave select pin.
The location of the pin plug ensures that it is a 2.5" IDE.

[RoGeorge]

The 3.5'' IDE disks used to have a 40 wires.

I assume the sideways hooks in the OP pics are as in the PC cable I've seen, they are to clip the upper with the lower side of the same (female) connector, after laying the ribbon cable in the middle for the first time.  Once the ribbon fully crimped, the sideways were allowed to latch with the bottom side of the connector, and never do be open again.  Once done that, the ribbon with the female connector crimped is good to insert into the male side of the connector.

Usually there was no locking mechanism between the male and the female connectors for such cables.  Friction alone was strong enough to keep them in place.

[tooki]

I don't know the part number, but it looks the same as the IDE (for hard-disk, CD-ROM, DVD unit, etc.) ribbon connector used in desktops, before they were replaced by SATA.  Except those were 40pins, not 44.  Same type of connector used for SCSI ribbons, except SCSI were 50pins.  They are often listed as 'IDC connector'.  Search for '44 pins IDC ribbon connector'. 

I see now the 3M name is molded-on socket:
https://multimedia.3m.com/mws/media/446388O/3m-molded-on-cable-assemblies-guide-3m-us.pdf?fn=Molded%20On%20Cbl%20Assm%20dynamic.pdf

The 3.5'' IDE disks used to have a 40 wires.

Bro… 

1. At no point has OP said they’re for hard drives.
2. OP already stated the pitch is 2.0mm.
3. Standard 40-pin IDE and 50-pin SCSI use a pitch of 2.54mm, so irrelevant here.
4. 44-pin IDE exists, and uses 2.0mm-pitch connectors. These are what parallel IDE 2.5” hard drives used.
5. No, the 3M molded-on sockets are a specific subtype of IDC connector for mass production. It is NOT 3M’s name for IDC sockets in general!! 3M makes many other IDC sockets that are not molded on.

[Crsus]

It has 'C044-03' and 'JAPAN' written on it.

[Crsus]

This is not the IDE used on ordinary computers, but a data cable for device hard drives. The hooks at both ends may serve to reinforce the connection with the seats on the PCB. This is my guess, but I haven't found the specific model.

[squadchannel]

Hirose A3E-50D-2R (but not perfect match)

https://www.hirose.com/ja/product/document?clcode=CL0621-0814-1-30&productname=A3E-50D-2R(30)&series=A3E&documenttype=Catalog&lang=ja&documentid=D49522_en

image search shows an image that seems to be the same, but perhaps because it is discontinued, the search results do not come up.

[Crsus]

It looks like it has been discontinued, so it's hard to find. But thank you very much anyway.

[tooki]

There are numerous equivalent, compatible parts from many vendors. Those Hirose parts look as generic as they come.

The ones you have, Crsus, are a bit unusual in having those little round bulges at the end. But chances are a normal 2mm pitch shrouded header will fit fine (especially if you look for one with slots in the ends) and if not, a 2mm pitch unshrouded header will definitely fit.

For example, look at Molex 87831-4421 and 87831-5021.

Regardless of manufacturer, you will need to pull out individual pins to mate with the connector with the keyed contacts (where the hole is blocked off with a white plug).

[tooki]

Hirose A3E-50D-2R (but not perfect match)

https://www.hirose.com/ja/product/document?clcode=CL0621-0814-1-30&productname=A3E-50D-2R(30)&series=A3E&documenttype=Catalog&lang=ja&documentid=D49522_en

image search shows an image that seems to be the same, but perhaps because it is discontinued, the search results do not come up.
(Attachment Link)
(Attachment Link)

It isn’t discontinued. A3E-50D-2R was replaced with A3E-50D-2R(30), which is just an updated version with a different material supplier.

[squadchannel]

"hook" type connectors may be discontinued.

yes, the Hirose ones are not discontinued.
in any case, can use any 2mm pitch 50-pin IDC.