Please understand that while we may temporarily lower prices, we generally do not accept price negotiations. Management Number: #5A617 This is a removed part from a Yamaha SC-3000 manufactured in the 1980s. Considering the business aspect, parts should have been standardized as much as possible, so it is likely to be a common part with other models. Based on my review of catalogs, etc., I believe it is compatible with the following models manufactured around the same time. (In addition, it may have been installed/used in other models manufactured around the same time.) SC700/SC800/SC1000/SC1200/SC3000/SC5000/SC7000 SJ500/SJ800 SA900/SA2500 SG510 SJ700HR/SJ700HM/SJ600SR/SJ600SM STH400R STH500R/500M STH800R/800M STH1000R * Personally, I think this knob is excellent in every aspect, including its size, side shape, the shape of the side notches, and the chamfering. It fits the fingers very well and allows for stress-free adjustment of the potentiometer. I have never encountered a knob superior to this in terms of functionality. This is a single item (one piece) for sale as shown in the photos. Although I have cleaned and polished it with a polishing agent before listing, the dirt may not be completely removed. For free shipping, the shipping method may be changed at my discretion.