Despite being mostly secluded. dark sector particles may feebly interact with photons via a small mass-dimension 4 millicharge. a mass-dimension 5 magnetic and electric dipole moment. or a mass-dimension 6 anapole moment and charge radius. https://www.roneverhart.com/A-Pea-in-the-Pod-Clip-Down-Nursing-Bra-Black-L/