Fill power is the space that 1 ounce of down occupies, resulting in its insulation quality: a higher number means bigger clusters, so the same amount traps more air (read: warmth) with less weight.
Eliasa – Eiderdown Pillow
For those who desire the unequivocal best: sleep above the enchanting comfort of The Eliasa eiderdown Pillow. Each pillow is composed of lustrous, pure silk stuffed with generous clusters of eiderdown. Eiderdown is the gold standard, the undisputed pinnacle in luxurious, natural fill—the finest, warmest, most inimitable, and exquisite down in the world.