Offer is the very rare vintage ITT image intensifier tube super large size 75mm diameter. I'm not sure about the model print label ITT Electro Optical Division on the acrylic housing is correct or not, model 41x0?? I can't see clear and read the model number due to the print label worn out. Both input and output are thick fiber optic faceplate, both are 75mm diameter, proximity focus, it seems the photocathode is the S25 type base on the violet material surface. This is the Gen 1 type, very high resolution, image display line pattern test is perfect, no distortion. It can be used for the R&D research labs or science optic project rather than simple night vision application. If using for astroscope project, it may need the huge super large lens to focus large size image on the front 75mm diameter photocathode. This tube is tested with the -5000 volt output Emco 12v DC-DC HV converter, very good high resolution image and low noise clear image, much better than Gen2 or Gen3 type. It has 2-3 very small blemish spot and 1 tiny 0.2mm tiny bright halo near outer diameter. Please see all pictures for more detail. This is the very rare tube image intensifier for your astroscope night vision science labs project. Thanks for watching the listing of this item.