RB-SD film back cover

I have seen something like this for RZ and 645 but not for RB....

Is there such thing as back FILM BACK COVER for Mamiya RB-SD? Behind that thin stainless steel darkslide is a delicate film, and the mating surface of the back is what seals the light from coming in. I'm thinking it makes sense not to casually toss backs into my carrying bag.

How do you carry your back? Carefully? Casually? Don't care?

At present I only have three backs. One stays on the body and the other two each have individual pockets in my soft side bag.

I don't worry about it. The darkslide interlocks would prevent it from ever coming out under normal bag conditions, and the clamshell seems pretty tight. Of all the tank-like parts of this camera, the backs are probably the most indestructible.

Zip loc bags in the carry box, they don't get dirt n sand in em. I shoot on beaches ever so often n found this is the best safety measure for everything.