This filter cube, Nikon B-2A is new item from a former Nikon dealer inventory. It will fit the Nikon 50I, 80I and TE2000/3000 Eclipse series of fluorescent Inverted  microscopes. It is in the catalog with a product number of 96302. The cube is in new condition and still in its' plastic bubble case. The plastic bubble case is not pictured.

The Nikon B-2A fluorescence filter set is designed to provide an expanded absorption window for fluorophores, when compared to the B-1A combination, by utilizing a medium sized bandpass excitation filter (40 nanometers) rather than a narrow excitation passband. The longpass barrier (emission) filter has a cut-on wavelength of 515 nanometers and is capable of transmitting a significant amount of the signal from green, yellow, and red fluorophores that have absorption bands in the central blue wavelength region. In addition, the B-2A combination employs a longpass dichromatic mirror with a cut-on wavelength of 500 nanometers, 5 nanometers below that of other filter sets in the blue-excitation series.