64MB, 144-pin, DDR2 SDRAM DIMM memory module
HP CB421-67951, 64 MB, LaserJet P3004, LaserJet P3005, DDR2, 144-pin DIMM, 1 x 64 MB
HP CB421-67951. Capacity: 64 MB, Compatibility: LaserJet P3004, LaserJet P3005, Internal memory type: DDR2