Genuine Hasselblad Proshade B50 Adapter Ring. To use on lenses with the B50 filter BAY with the Proshade Catalogue number 40676. For all Hallselblad C and F lenses with B50 bay mount as: Planar 80mm, 100mm, S-Planar 120mm, 135mm, Sonar 150mm, 250mm.etc.
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