This is Yamaha YSL-456G trombone with F attachment. It is a current model in Japan and Australia, but has never been introduced in the USA. The Australian version is designated as YSL-456GA, which is essentially (if not exactly--I am not 100% sure) the same instrument, and was played by James Morrison before he made the switch to Schagerl. It is an updated/upgraded version of more common YSL-356G and its predecessor YSL-356R, both of which were sold and enjoyed popularity in the US in the past. (356G, by the way, is still current in Europe. My personal feeling is that the 456G plays better than either of 356 variations, in the order of 456G>356G>>>356R.)This trombone has a .500"/.525" dual bore, meaning that its slide has different diameters of tubes making it more gradually expansive. It is a feature used in many legendary trombones such as King 2B, and is said to give the ease of playing smaller size trombone with the richness in sound of larger size trombone. To me it is a great in-between size that I can play in a chamber orchestras, wind ensembles, and brass quintets when I want a lighter sound than a large bore trombone (to me a medium bore .525" is too close to large bore sound in this situation...). I could see myself playing it in second or third chair in the big band, too, if I play in one. But the most useful situation for me by far has been musical theatre show pit. It thrives in that situation. And F attachment helps a lot--actually a "must" in a small pit with limited space!The bell is 8", which I think is a good size, too--Yamaha's .525" trombones have 8.5" bell, which works wonderfully in certain situations, but I think the focus I get from a 8" bell is also useful in this size of trombone. The bell/slide connector is the same size as Yamaha's other .525" trombones (NOT the same as .500" or other smaller size models), just so you know if you are thinking about mixing and matching with other models.400 series Yamaha trombones are considered "intermediate" or "step up" grade instruments, but many are previous professional models re-numbered when newer models came out. This particular model does not have such legacy, but is made at the same high standards of craftsmanship. Some of the recent 400 level models sold in the US come out of Yamaha's Shanghai factory in China, which is by no means inferior--but this particular trombone was made in their headquarter factory in Hamamatsu, Japan!I would say it in in excellent condition. No major dents, lacquer at 98%, all slides work smoothly and as does the valve, ready to play right out of the box. There are a couple of scratched spots on the bell flair (see picture #11). Comes with original case in good condition. Also has original mouthpiece (Yamaha 45C2) in very good condition (I would usually prefer something a little bit larger with this trombone, personally--45C2 is about the size of Bach 12C).Thank you for looking!