A Raw Silicon Chip (DIE) , as found prior to lead attachment and encapsulation. This is purely a curiosity / educational item rarely found outside the factory. looks very impressive under a microscope. comes with datasheet showing die layout, which can actually bee seen on the chip without a microscope. actual die is an APEX CPA28 op-amp. these dies's probably would be used as component of a dedicated hybrid device i.e a much larger circuit built up of many chips built into a single package.. price is per single chip, (box shows 49 chips) each chip is approximately 5 x 4.5mm