HP LaserJet Pro 400 color Printer M451 series - Manual (Page 73)

Table 6-2 Supported envelopes and postcards (continued)
Size Dimensions Tray 1 Tray 2 Automatic duplex
printing
Envelope B5 176 x 250 mm (6.7 x 9.8 inches)
Envelope
Monarch 98 x 191 mm (3.9 x 7.5 inches)
Postcard 100 x 148 mm (3.94 x 5.83 inches)
Double
postcard 148 x 200 mm (5.83 x 7.87 inches)
ENWW Supported paper sizes 55