High quality magnetic stainless steel (alloy 430) discs for Atomic Force Microscopy. They measure 20mm and come in a 50 pack.
High quality V1 muscovite mica disks that come interleaved in a pack of 10 in four different diameters used in AFM calibration. (15mm size)
Fast drying, alcohol based silver conductive paint for sample mounting and electrical continuity.