Picture is just an example. Markings may vary. There may be cosmetic imperfections.
8087 math co-processor for 8088 and 8086 computers.
A 10MHz rated one will work in any motherboard to 10MHz.
A 5MHz rated one will work in any motherboard up to 5MHz.
The speed it runs at is set by the motherboard, not the chip. For example, it will run at 4.77MHz if installed in an IBM PC 5150/5155/5160.
40-pin Ceramic DIP package.