WQQZJJ Set of 14 Invisible Pen Fine Tip Invisible ink Maker Kids Message Pen with Built in Light: Specifications: Color: black, blue, red, green, purple,, yellow Ink properties: Invisible ink Size: 13.4cm/5.28in material: PP Package includes: 14 pens Note: Please Allow a little Difference Due To Manual Measurement.Besides Different Computers Display Colors Differently, The Color Of The Actual Item May Vary Slightly From The Below Images Thanks For Your Understanding(1 inch = 2.54 cm),Please Kindly Check It Before You Order Our Product,Thanks. when you the light on to them, the behind reveals For saving batteries life, plug the write card tag back to the pen when you don't use the light Please don't the light directly to eyes You can have private conversations with this invisible pen school highlighters, highlighters, highlighter, highlighters assorted colors, highlighter pens, highlighters no bleed, cute highlighters, highlighters pastel, pocket highlighters,highlighters bulk bible highlighter