Cooke's cal-LIGHT400 Series of Calibrated Digital Lightmeters provide accurate measurements in user-selectable foot-candles or lux. Individually calibrated to NIST standards, each unit includes a carrying case, battery and calibration certificate. Used world-wide. Wherever lighting is important - accurate measurements are important too! Whether the user is in Maintenance, Health & Safety, a Facility Manager, an Architect or Designer, in Law Enforcement, or a Lighting Designer or Specifier, a calibrated light meter is needed. Illuminance measurements are necessary for many reasons (for safety purposes, in designing spaces, to save energy), and our hand-held ergonomically designed meter can be used anywhere -- schools, offices, parking lots, stairways, libraries, warehouses, museums & art galleries, stadiums, arenas, highways. Check your Light Levels -- Accurately!