Far-IR and terahertz bandpass and narrow-bandpass filters with center wavelengths from 15 to 200 μm have been released by Lake Shore Cryotronics Inc. Patterned cross-shaped holes allow transmission of light at specific wavelengths. Center wavelength transmission of up to 80% with tolerance of ±0.1 μm and out-of-band transmission down to 0.5% have been achieved. The 1-mm-deep filters can be integrated into existing filter wheels, cryostats or compact optical instruments. They deliver stable and repeatable performance down to 4 K. The filters are available in diameters of 12.5, 19.0 and 25.0 mm. Applications include astronomy, FTIR and terahertz spectroscopy, and electro-optics research and testing.