The LaserLyte Laser Cartridge Trainer & Bore Sight (MPN: 1226990) is a dual-purpose .40 S&W brass cartridge. It allows users to easily align iron sights or optics and enables firing-pin-activated dry-fire practice at home. The 1226990 includes two swappable end caps that switch the device between its two primary modes: Bore Sight Mode: The constant-on end cap provides an accurate, steady laser point to quickly align scopes and iron sights without live ammunition. Trainer Mode: The firing-pin-activated end cap emits a split-second red laser flash with every trigger pull. It is highly useful for dry-fire training and pairs with LaserLyte electronic targets for immediate visual feedback.