This 1.5X24 night vision monocular objective lens is a changeable lens for GEN.1 tube monocular 2x42, 2x50, 4X50, 6X50,8X50 etc NV monocular for Yukon, ATN monoculars, And fit for 2x50,4x50 etc NIGHTSTAR products. When it replace for digital night vision monoculars of NIGHTSTAR, it become 3x24 lens.  This make your product more lightweight and with wider field of view, at some extent can be mounted on Helmet for hand free observation. Don't miss out on the opportunity to enhance your night vision experience with this low power device.  Before purchase, please make sure the thread and connector diameter is fit for your device!   Not recommend it for replace NIGHTSTAR 2X42 NS41242C lens!