Compatible with Hewlett Packard LaserJet 4050, 4050n, 4050t, 4050tn; 4100, 4100n, 4100dtn, 4100tn; 4200, 4200n, 4200dtn, 4200tn; 4300, 4300n, 4300dtn, 4300tn; 9000, 9000n, 9000dn, 9000l; Color LaserJet 2500, 2500L, 2500N, 2500TN, 2500EN; 2605, 2605dn, 2605dtn and 2700 and 2700n. DO NOT use this ram on printer models other than listed above. Contact us if you have any questions.