NISP flight model, before wrapping in light-tight multi-layer insulation. Light enters the filter wheel and grism wheel enclosure (left) through a collimator lens, hidden behind the large round wheel enclosure. A triplet camera lens assembly projects the beam onto the cold detector system at the right end of the structure, with the readout electronics to the very right. The NISP calibration lamp is located to the top left of the camera lens assembly in this picture. See Euclid Collaboration: Jahnke et al. (2025) for details.