|Vredeborch Felica Duo|
image by Paul-Henri S (Image rights)
In the late 1950s, Vredeborch offered a variation on the Felica where the 6x6 frame size could optionally be masked to 6x4.5 cm —hence, "duo." An added lower red window aligned with the 16-exposure numbering on the backing paper of 120 roll film. The Stafetta Duo is a name variant of the same camera.