LITEON used PSU ATX 310W, PS-5311-7MWA-ROHS 

Compatible with Lenovo M55/M55P

Connections:
1x 24-Pin ATX
1x 4-Pin ATX 12V
4x Serial ATA
1x Floppy Disk

Lenovo Part No: 41N3451
PSU για Lenovo ThinkCentre M55/M55P Tower