Features of Digital Sound Level Meter Lutron SL-4011: Accurate sound level measurement for industrial and environmental applications Wide measurement range for versatile noise monitoring Fast and slow response time selection A and C frequency weighting options Easy-to-read LCD display Data hold function for convenient reading capture Max hold function to record peak sound levels Compact, lightweight, and portable design Durable construction for field and industrial use Ideal for workplace, factory, HVAC, and environmental noise assessments Simple one-hand operation Low power consumption for extended battery life