Top: front perspective mechanical drawing of a polarization-sensitive bolometer (PSB). The illustration shows the forward/upper portion, i.e., PSBa, of the PSBa/b pair. The orientation of the PSBb absorber is orthogonal to the PSBa. Bottom: mechanical drawing of a spider-web bolometer (SWB). In both figures, the printed wiring board (PWB) and cover are not shown. The size of a HFI bolometer module (including the thermometer, the absorber, the silicon die, the housing and the backshort) is between 1.5 and 1.9 cm depending on the working frequency.