The KBr Window Kit for the Spectrum Two is a replacement window set for this spectrometer. The kit consists of a right-side window assembly and left-side window assembly. These windows are made of potassium bromide and can be used up to 300 °C.
KBr has a slightly wider spectral range than NaCl but is more hygroscopic. Although able to provide good resistance to mechanical shock, KBr is easily cleaved.