What is a fuel pump nib?

so i went on ebay to buy a fuel pump for my 2002 nissant sentra GXE and found this fuel pump nib which was very cheap. I bought it without thinking. now that i took my fuel pump out i cant figure a way to use the motor and the filter that came with it with the pump. what i wanted to do was open the pump and see if i could change the filter and the pump on the old one and put it back. but i thought i ask here first before i open the product from its wrap so i can return it if it is not working for me. thanks