Waterproof Flashlight and Marker Light. With its small body and lightweight design, the Princeton Tec Amp 1L is perfect for use as a secondary flashlight or marker light. With its over-molded grip, this light fits very comfortably in your hand for use as a flashlight, and equipped with a snap-on translucent cone, it has the ability to transform into a marker light or area light. Rated IPX8 waterproof, this flashlight is ready for any demanding environment, and, with its incorporated bottle opener, ready to relax after a long adventure.