Please understand that while we may temporarily lower prices, we generally do not negotiate discounts. Management Number: #5A624 This is a part removed from an 80s Yamaha BB-VI. From a management perspective, parts were likely standardized as much as possible, so it's likely a common part with other models. Based on my review of catalogs, it appears to be compatible with the following models manufactured around the same time (and may also have been used in other models manufactured around the same period): BB800/BB1000/BB1200/BB2000/BB3000/BBV/BBVI/BBVII/BBX/BBVIS/BBVIIS/BB2000SSB500/SB600/SB700/SB800/SB500S/SB800S/SB1200S *In my personal opinion, this knob is excellent in every way: size, side shape, the shape of the side ridges, and the chamfering. It fits the fingers very well, allowing for stress-free adjustment of the pot, and I have never encountered a knob superior in functionality. This is a single item (one piece, individual) for sale as shown in the photos. It has been cleaned and polished with polishing agents before listing, but not all dirt may be completely removed. For free shipping, the shipping method may be changed at our discretion.