These are 5 pin sockets for common automotive relays. They are sold in packs of 6 sockets with 30 crimp on terminals that fit up-to 12 gauge wire. Each pack also includes a basic diagram for pin location. They are available in packs of 25 and 50 as well. Check my other auctions for bulk relays. e-mail with any questions. This socket is used for common 4 and 5 pin relays. 4 pin simply do not use the center pin location of this socket.