tElement 36pcs Magnetic Holder Lifter Fastener Stick Adhesive 1/4" 6mm Round Cylinder Magnets

Are these actually neodymium?

What is the magnet grade? i would love to find something in this shape that is n35 or greater, with a sh or uh temperature rating.

Are they 1/4" (0.250") or are they 6mm (0.2362")? There's a significant difference.