■ Product Name / Lazer-Stik Battery Powered Marker Light ■ About Innovative Scuba Concepts This company, headquartered in Colorado, USA, began in 1988 with the invention and patent of a cover made of neoprene fabric for diving mask straps, a familiar product for divers. Subsequently, they created "The-Quest," the world's first innovative tool allowing divers to communicate underwater by writing and erasing with a magnetic pen. This became a hit product, essential for diving instructors and underwater guides worldwide. Currently, they distribute over 4,000 diving-related accessories globally. ■ How to Use Before entering the water for night diving, attach the marker light to the yoke screw of your regulator's 1st stage and turn it on. Upon entering the water, the marker light's buoyancy will cause it to float upright above the yoke screw, allowing other divers in your group to see your location even from a distance. In the past, when marker lights weren't available, it was common to use chemical lights. These lights used a double-layered polyethylene body that, when bent, mixed the luminescent substance inside with the outer liquid, causing a chemical reaction that produced light. However, chemical lights are single-use and cannot be reused, leading to environmental concerns from a sustainability perspective. In recent years, battery-powered penlights have become the mainstream choice, even at live venues for artists, due to these considerations. The light uses three LR44 alkaline button batteries, which are small but powerful, with an operating voltage of 1.5V. With new batteries, the light can flash for 20 hours, significantly reducing running costs compared to similar products from competitors. The ON/OFF function is a simple screw-in design, and the entire stick-shaped lens emits a very bright red flashing light. It is waterproof to a depth of 350 ft. This product holds U.S. Patent D391,653 and Canadian Patent 82779. ■ Size / Total Length: 15.5cm, Outer Diameter: 2cm (Bottom)