I use this Fantastic little gadget to illuminate and read my charts and navigation notes. The LED’s only illuminate the Perspex and underlying paper or chart and not your surrounding area. I also modified mine and changed the white LED’s for red which enhances the device for even better night vision protection. I found it amazing as it only illuminates the paper and not surrounding area. You can buy it on Amazon and other reputable on line stores, minus the red LED’s off course, but white works well also, if you don’t fancy modifying. I think red were also available, but I can’t seem to find them on line anymore ? Also good for not waking up your partner when reading at night ?⛵️