HP LaserJet PRO M521 Repair Manua page 177

Table 2-16
Ref Description
1 Optional 500-sheet tray and feeder unit
2 Base-plate roller assembly
3 Separation holder assembly
4 Cassette, Tray 3
ENWW
500-sheet input tray (Tray 3)
Part number
CE530-69001
RM1-6306-000CN
RM1-6303-000CN
RM1-6279-000CN
Input devices
Qty
1
4
1
1
167