Mouser
PLUGBOARD CARD EDGE NPTH - Digikey
PCBs & Breadboards IBM AT 13.25X4.8 - Mouser
PCB PLUGBOARD, IBM AT/ISA CARD EDGE, 3-HOLE PADS; Board Type:PCB Card Edge, Pre-etched Pattern; Board Material:Epoxy Glass Composite; Hole Diameter:1.067mm; External Height:121.9mm; External Width:336.55mm; Board Thickness:1.57mm ;RoHS Compliant: No - Newark