This sale is for a mint condition and super rare Mamiya RB/RZ67 No. 4 Lens Pouch, made specifically for the RB67 and RZ67 37mm fisheye lenses, but also suitable for the 75mm shift.
This is the safest and best way to store your very expensive fisheye. Really hard to find.
There are almost no signs of use; this pouch really is in superb condition.