This kit has been discontinued. Take a look at individual products: SL355 and 407766
Extech SL355-KIT-3

SL355-KIT-3: Personal Noise Dosimeter/Datalogger Kit

Includes three SL355 Noise Dosimeters with microphones, 407766 Sound Level Calibrator and USB cable

For employees that are exposed to loud noise, sound level monitoring is essential to determine what protective measures are required. Perform OSHA and IEC Noise accumulation surveys to determine total sound exposure over an 8-hour period. The SL355-KIT-3 comes with three compact, lightweight Dosimeters with USB interface designed to test noise exposure and provide noise surveys for compliance with OSHA, MSHA, DOD, ACGIH, and ISO standards. Includes PC software to control setup and retrieve stored events or analyze real-time measurements.