I long ago replaced the factory tripod collars on my Nikon 80-200/2.8 and 300/4 with much more stable, low-profile collars from Burzynski, so when I bought a Panasonic 100-300mm zoom for a trip to the UK last summer I looked around and a couple of references to the collar made by Rösch Feinmechanik. Time was short, however, so I put the search off until a future time. I recently decided that now was the time, so I emailed the maker to inquire about availability and final cost delivered to the US. The result was that, 74 Euros (about US$100) and nine days later I had the tripod collar on my desk. I haven't had time to use it yet, but I wanted to let people here know that this collar is available and looks very promising. The specs from the website (translation courtesy of Bing): -black anodized high-strength aluminium alloy -simple Assembly without tools -ergonomic captive screw -high stability with lens-friendly clamping -Weight only 70 g -two tripod holes for balance -small size, can remain this way permanently on the lens -Using the lens hood in both directions possible -vertical and horizontal application without limiting the switch My observations so far: This is very well made - comparable to the Burzynski collars in all respects other than not using a Delrin ring inside the collar. As the instructions that come with the collar note, if you rotate the lens in the collar to shift from landscape to portrait with any frequency you may notice rub marks on the lens barrel finish. The collar is available in two versions, one of which has an Acra-compatible foot as well as the two 1/4" standard tripod holes on the other version. (Both collar versions apparently cost the same.) In informal indoor use, I've found the collar very easy to use, both hand-held and on a tripod. Its low profile not only helps rigidity but makes it easy to cradle in the left hand. Access to the zoom ring is affected slightly, but I found the Panasonic accessory zoom lever (which I had on the lens previously) still works well for zoom control after attaching the collar. Furthermore, the lens fits into the Panasonic lens bag, and into my shoulder bag, easily with the collar attached, and adds very little bulk. A side note on the Panasonic accessory zoom lever - I find it moderately beneficial, but I wouldn't say it's by any means necessary, and some might find it annoying. At the time this was posted, the cost from major dealers was around $US25. You can see it mounted in the pictures below: it's the thin black ring mounted over the zoom ring, just forward of the collar ring, with the small black lever sticking out. Again, it's personal preference. I got used to levers 40+ years ago on Leica lenses (though that was on the focusing ring, obviously, not a zoom ring at that time.) So far, this seems like a highly useful addition to a lens which really benefits from a stable mount, and the cost and shipping time seemed very reasonable to me. There are some quick pictures below...pardon the dust!