Help identify

This is a gear reduction wind up assembly that would connect to a roll up door, used in commercial buildings for large bay doors. Would be powered by a small to medium size electric motor to power up and down. Would also have a hand operated chain option too. The hole surrounded by five smaller hole next to the gears mounted on the assembly, would have a bearing bolted to it and the spindle shaft for the door itself would go thru it and have the largest gear attached to the end. Opposite side of the door would have a similar assembly minus the gears and chain.

References:

Worked in a Manufacturing shop that had several of these door winders.

Reason:
I can't find a matching assembly online. Could you find an exact match and send me the reference (url) link.

I don't understand how the previous answer was rejected. It is 100% correct. This site seems like a scam based on the rejected answers.

References:

Work in industrial environment with multiple roll up doors using these mechanisms.

Reason:
the reason I rejected it is because I asked the expert little more information and to provide a reference link to exact item as I could not find it by searching google. If you can please provide a reference link and I can accept you opinion.

Door Chain Hoist Model Reduction Wall Mount

References:

https://store.preferreddoorservice.com/garage-door-chain-hoist-model-2000r-4-...

Reason:
Thank you for the opinion , but the one I have looks different from the one you reference