O2 Sensor wiring to ECU

[lugbutz]

Hi

I have another question this time about how the O2 sensor connects thru to the ECU

I installed a new O2 sensor amd when i removed the old sensor I damaged the old bakealite connector.
When i went to repair that connector i noticed the wiring which runs back to the ecu has 2 layers of wiring. So you have a exterior layer of insulation, a layer of wiring, another layer of insulation followed by a core of wiring.

My questions are
1. What is this called?
2. Do i need a special connector, if yes... what is the connector called and where can i get one?
If no... how do i install a new connector? Can injust use a spade connector?

J