RE: RC Lander Lighting System
By the looks of these photos, there's different rings offered.
3 photos of the green ring, My guess only, is the 70mm ring. the other photo is the, my guess again, 90mm ring.
Clearly, the 70mm or green ring is constructed "cleaner," that is the thickness of the ring is smaller than the one in the other photo.
One would guess why? Also seems as though there's more thickness in the other ring than necessary.
They don't make it easy for you.