Trackball rollers for Bernina 1530 & 1630

These look like the offerings elsewhere - they are not! These work! Installed easily and effortlessly. They are nice and squishy like the original foam rollers, but they have a resilience the originals lacked (after 40 years) Sold as a set of 4 so even if they fail at 5 years I have another set (probably outlast me now) Brilliant and cost effective way of getting my beloved 1630 back to work, I would pay way more if necessary. Thank you!!!