Fuser Roller
The following printers are built around the same interchangeable set of parts.
The T650n is the entry level network laser printer built around the 4062 machine
The T650dn adds a detachable duplex unit for double sided printing.
The T652dn adds a 550 sheet paper input tray and the duplexing unit is now integrated.
The T654dn adds an increased printing speed.
The T656dne adds a touch screen.
The X651de adds a multifunction document scanner / copier. The X65x range is built around the 7462 machine but the parts appear to be interchangeable with the 4062 machine.
The X652de adds a fax function
The X654de adds an increased printing speed.
The X656dte adds a detachable second paper tray and an 80GB hard disk.
The X658dfe, X658dme, X658dtfe, X658dtme integrate a larger output tray with offset stacker and stapler.