The Brother KR-850 Ribbing Attachment for standard gauge 4.5mm knitting machines is a white wool unit designed by Brother. This accessory is specifically for the Brother KR 850 model, making it a reliable and compatible choice for knitting enthusiasts. The ribbing attachment helps create professional-looking ribbing for a variety of knitting projects, adding texture and style to your work. Ideal for those looking to expand their knitting capabilities and achieve high-quality results.good condition there is another clamp.please look at all the photos there isnt any rust.thankyou for looking.