I read reviews elsewhere online about this adapter not seeming stable and/or the car seat wobbling and moving when attached to the adapter on the Valco Neo Twin stroller, so I thoroughly checked it out with my infant car seat. There is some movement with just the metal ring adapter BUT if the included straps are used appropriately (they attach to the stroller frame) and tightened in the car seat’s belt path, the seat seems very stable and secure. The included manual does tell users to always use the straps, but I suspect the people complaining about the adapter shifting either aren’t using the straps or did not attach and tighten them properly to the stroller frame. The adapter has to be removed to fold but the straps can stay attached to the stroller frame.
I’m subtracting a star for the lack of clarity in the car seat manual - there are no indicators on the actual adapter or in the manual about which way the adapter is supposed to face, or where the straps should be positioned on the stroller frame. I was able to figure it out but the manual should have had clear instructions and diagrams to minimize confusion and ensure correct use.