More Telecom Tools Identification

[SUnset2]

I recently got a group of telecom tools.  Most of them were readily identifiable, but there are some that puzzle me. 

No. 1 has two thin contacts at the front, and two wings at the back that look like they are for connecting a buttset. 

No. 2 has four pins on one side and four turrets at the top.

No. 3 has six round pins, and no other connections.

No. 4 has the same 6 round pins as No. 3, four buttset terminals on the sides, and an RJ11 on the end.

What do these plug into?

[TelePlay]

#3 and #4 could be a older variation of this:

https://www.westek.com/collections/network-test-tool-kits/products/tel-line-tester-pro

[SUnset2]

#3 and #4 could be a older variation of this:
https://www.westek.com/collections/network-test-tool-kits/products/tel-line-tester-pro

I found that, but I can't figure out what they would plug into.

[Jon Kolger]

Number 3 is a protector module that plugs into a telco MDF (Main Distribution Frame)  protecting the central office equipment from external foreign current such as lightning or AC power.  There is one of these modules on every single cable pair leaving the Central Office (CO).  Number 4 is a test module that separates the CO side of the line from the outside cable.  The RJ11 jack allows a technician to plug a test set or telephone into  (I believe) the CO side of the line.

[dsk]

No 1 may be a krone plus plug for measuring.   

[SUnset2]

Number 3 is a protector module that plugs into a telco MDF (Main Distribution Frame)  protecting the central office equipment from external foreign current such as lightning or AC power.  There is one of these modules on every single cable pair leaving the Central Office (CO).  Number 4 is a test module that separates the CO side of the line from the outside cable.  The RJ11 jack allows a technician to plug a test set or telephone into  (I believe) the CO side of the line.

So I'm not likely to encounter this connector outside of a CO?

[SUnset2]

No 1 may be a krone plus plug for measuring.   

It could be, there was a Krone punchdown tool in the lot of tools.  It doesn't match anything in a 66 block.