Can you identify this component?
It's a snap-on ferrite core which, when clamped over a number of conductors, becomes part of a common-mode choke. Here is a complete datasheet for a similar product. 

The ferrite is lossy so it is better characterized as an impedance at a given frequency. In the case of my example, every wire that goes through the core behaves like it has 241 ohms in series @ 100MHz but only for common mode voltage. If current is going in and out through a pair of conductors the magnetic fields cancel and it acts pretty much like a pair of wires for that current. Unbalanced current (say to ground) will behave like it has the impedance in series. 



It is very important to make sure that all the wire pairs that carry significant current are contained within one core, otherwise the core will saturate and the benefit will be lost. 

A typical application of such a core would be for wiring to a noisy source such a VFD (motor drive). 

Looping the wires \$n\$ times through the core will increase the impedance by a factor of \$n^2\$. Again, every wire must be looped the same number of times to get the full benefit.