QHYCCD QHY9 - Manual (Page 5)

2) Accessories
1) M42 (male) to M54 (male) adapter
Mounts camera to optional filter wheel
2) Optional M42 (male) to M42 (female) optic window (AR+AR or IR+AR)
Helps avoid the CCD chamber sealing glass from condensation when humidity is RH>65%
3) Special 9-pin power cable, 2.5 meter length