Add a layer of security to your printing environment. With HP High-Performance Secure Hard Disks, you can easily help secure valuable data at rest on your HP LaserJet printer or MFP. 1 GB 90-pin DDR3 DIMM-Dual in-line Memory Module for Printer. Compatible with HP LaserJet Enterprise M604DN,M604N and HP Color LaserJet Enterprise M553DN,M553N,M553X. Accessory Type: DIMM; Dimensions: 7 x 5.25 x 1; For Use With: HP LaserJet Enterprise M553dn, M553n, M553x, M604dn, M604n.