The NovaTac Programmable Series flashlights are designed for true flexibility. They can be programmed by the user to produce hundreds of light intensity and operational combinations. The 120P offers a flat button and four configurable brightness settings ranging from .3 Lumens to 120 Lumens. The system has up to 22 available brightness levels in addition to three choices of signal levels (Disorienting Strobe, Emergency Strobe and SOS Signal). The NovaTac P-Series Flashlight is the toughest, most versatile light you can buy. Performance Features: 4 Programmable Brightness Levels Primary Setting: 10 Lumens Secondary Setting: 30 Lumens Minimum Setting: .3 Lumens Maximum Setting: 120 Lumens Options Menu, ramped brightness settings Extended Button Durability Features: Stainless Steel Crenulated Lens Nut Polycarbonate Lens Aerospace Aluminum Housing Military Type III Hard Anodize Withstands Severe Impact, Temerature Extremes and Weather Conveniance Features: Single-Button User Interface Pocket Clip/Lanyard Attachment User Manual Automatic Brightness Reduction for Weak Battery Protects Rechargeable Battery Reverse Polarity Protection Thermal Regulation Product Specifications: Input Voltage: 1.8V to 4.5V Light Source: White LED Maximum Light Output: 120 Lumens Regulation: Constant Power Regulation Battery: 1xCR123A or Li-ion (4.2V) Rechargeable Lens: Polycarbonate with Anti-reflective Coatings Dimensions: 1 Inch (25mm) Diameter by 3.3 Inches (80mm) Long Weight: 3.1 Ounces Including Battery Waterproof: 66 Feet