This format set is a 4x5" back adapter for a 6x9cm F-Metric Camera.
It consists of a 4x5 F-Metric rear format frame with geared rise, a 4x5" film back with groundglass frame and fresnel screen and a standard 6x9-4x5" 38cm, synthetic conical bellows.
Arca-Swiss 4x5 Back for 6x9 F-Metric Format Set - Standard
4x5" F-Metric Rear Format Frame (062011)
4x5" Film Back, Groundglass Frame, Fresnel Screen (080007)