Oki C610 - Manual (Page 16)

16 – C610/C711 User’s Guide
Duplex Unit ____________________
This option provides automatic two-sided printing on the same
range of paper sizes as tray 2 (i.e. all cassette sizes except A6),
using paper stocks from:
• C610: 17-32 lb. US Bond (64-120 g/m²)
• C711: 17-59 lb. US Bond (64-220 g/m²)
Note:
The duplex unit comes as standard with dn models.