Viridian Green Laser Sights Built for Walther P22 and PK380 Features highly visible green laser for visibility up to 100 yards in broad day light and up to 2 miles at night. Fully ambidextrous featuring SMARTLASER technology which offers 4 different operating modes. Up to 7 hours of runtime on 1 CR2 3 Volt Lithium Battery (included). Weighs only 2.4 ounces including battery--constructed of high strength Zytel polymer.