What is the drum unit for the HL-L2325DW and how long does it last?

The compatible drum unit for the HL-L2325DW is the DR-730, with an approximate life of 12,000 pages based on 1 page per job using A4/Letter simplex pages. The actual number of pages may be affected by factors including media type and media size. When it is time to replace the drum, an error message will appear on the machine's control panel or in the Status Monitor. (Page 12)