Lens Hood for Helios-44m-7 58mm f2 (52mm)

This is a lens hood for the Helios 44m 7 58mm f2.
I use it on my Sony a6000 with a speed booster adapter. This gives me the full field of view of the lens not a croped view (plus it gives me extra stop).
So I designed the hood with the following in mind :

1. To work with the full field of view (no vignetting)
2. You can put it upside down to make it compact - store it with the lens.

Note.
The length is for a Helios lens with an adapter or speed booster.
If you have the lens with no or smaller adater you cant pout it upside down .