One complaint of the Seiko SKX range is the 7s26 movement which is used.
Hacking & hand winding are not available on this movement.
The NH35 / 4R35 has hand winding & hacking capability & fits right into any Seiko SKX. (Date at 3 hour position)
A popular product for those wanting to mod their current Seiko & upgrade their movement.
*Movement comes securely packed in a miniature custom plastic box.