DE1209-68 is a ferrite core made by Fair-Rite®, part of the DE Series of parts. The core is made of ferrite material (magnetic material) and is used for common-mode noise suppression, power line filters, output coupling, and more. The "DE" name is derived from the two part numbers, DE1209 and 68. The first number, 1209, indicates the material grade (high-frequency material with an initial permeability of 5000), and the second number, 68, indicates the calorimetric grade of the material (1700 degrees Celsius).