https://www.guysmagnets.com/alnico-magnets-c20/guys-magnets-4-mm-x-20-mm-alnico-rod-p167 2026-09-01 daily 0.4 https://www.guysmagnets.com/alnico-magnets-c20/guys-magnets-5-mm-x-19-mm-alnico-rod-p169 2026-06-02 daily 0.4