I am actually surprised how well it has been doing. It was barely a spec when I bought the Duncan about 2 months ago, now there are several of these (some out of picture on the other side of the Duncan) and is slightly shaded under the duncan heads. The feathers seeam to just about reach the Duncan tentacles. the reason why I asked what this was, is because I noticed the Duncan head it was attached to was not opening as much as the others, so, of course, I got concerned.