MVIS-CIRPenSm: Magenta (Red) Visible and Clear IR Writing Pen $9.50 each + – Add to cart The add to cart button will appear once you select the values above Contact us for more information Magenta (Red) Visible and Clear in the Infrared above 800nm Writing Pen. This pen writes magenta in visible light and buts becomes transparent when viewed with an IR sensitive camera above 650nm.