TDK Life on Record Disc Safe Markers are specially formulated for safe, permanent disc labeling. Unlike some soft-tip markers, TDK Disc Safe Markers are non-abrasive and non-toxic. Abrasive markers can compromise the disc surface, damaging the recording material and introducing data errors. Each pack of TDK Disc Safe Markers includes four different color (red, green, blue and black) pens. Use TDK Disc Safe markers to track and identify your important data.