Berg offers test bars and test rings from Magnaflux for use in magnetic particle inspections. Test bars and rings imitate surface and subsurface defects to ensure that your magnetic particle system is measuring them accurately. Please browse our products to find the best one for you. If you have any questions, please give us a call at 1-847-577-3980 or send an email to info@bergeng.com. Our knowledgeable staff is there to help and assist you.