5-LOT Genuine Dell W1668 F2854 Black PS/2 Ball Scroll Wheel 2-Button Mice, Plug-N-Play NO SOFTWARE REQUIRED For Opperation, Works on All Computer Systems That Support PS/2 Connectivity, Compatible Dell Part Number: G4220 ~5-LOT~Genuine Dell PS/2 Ball Mouse with Scroll Wheel and Cord PS/2 Connection 2-Button and Scroll Wheel Plug 'n Play Dell Part Numbers: F2854, W1668, G4220