Jantzen C-Coils are Toroidal cored inductors of extremely high power rating and extremely low DCR.
The C-Coil is wound
around a toroidal sandwich core.
It has extremely low resistance and
can shift a large amount of power without getting over heated.
The core is formed like a donut with a round cross section and is wound from one long piece of laminated steel tape.
The surface of the core is epoxy coated to secure against short circuit even at a very high load.
If the stated maximum power is not exceeded the core will never saturate.
Typical handheld LCR meters measure at 1,000 Hz and will read a lower value than labelled. This is not a fault of the inductor.
Limited stock kept locally but available by special order in a range of 0.41mH to 38mH, In 12AWG to 17AWG
Tolerance of 5%
Sorted by value then gauge.