BW Technologies by Honeywell is the world's premier manufacturer of personal gas detection equipment. These instruments are small, lightweight, rugged, and easy to use. All instruments in the Gas Alert series operate in a similar fashion, so if you are familiar with one instrument then you will be familiar with all of them. Just open the box, turn them on, and they are ready to protect you from the gas hazards that are present in the workplace. Calibration is a simple procedure that only takes two minutes on average and all instruments have a countdown timer to alert you when the instrument is due for calibration.