MB2442, MB2546, MX421, MX521, MX522, XM1242, XM1246 MFPs 用户手册 这份《MB2442, MB2546, MX421, MX521, MX522, XM1242, XM1246 MFPs User's Guide》介绍了Lexmark的MB2442, MB2546, MX421, MX521, MX522, XM1242, XM1246 MFPs的使用方法,包括安全信息、产品规格、操作方法等