Swapped this onto my old fuel bottle and it clicked right into place, no wobble at all. The push-and-twist action is stiff enough that I'm not worried about it opening in my pack, which was the whole reason I bought it.
Carter★★★★★
The push-and-twist mechanism takes a bit of getting used to, but now I actually trust the cap around my kids. It fits my post-1981 bottle perfectly with no leaks.
Stella★★★★★
Swapped this onto my old fuel bottle and the push-and-twist takes a firm two-handed grip, which is exactly what I wanted around curious kids. Fit my post-'81 bottle perfectly, no leaks on the last trip.