The Stabila 39340 Type 196LED "The Lights" spirit level, 48" in length, includes optimal clarity, provided by two illuminated, easy to read vials and two removable light packs. LED light packs double as convenient flash lights. No wires or light bulbs go bad in the frame. Easily replaced AAA battery provides 5 hours of continuous use (approx 600 uses). Dependable magnetic switch with large button is easily accessed, even with gloved hands. Other features include auto shut off after 100 seconds and IP54 dust and waterproof rating. One Horizontal (level) and two Vertical (plumb) vials - vials are guaranteed for life.