The OptimAir 3000 PAPR portable air purifying respirator offers a lightweight (less than 1.5kg) unit with simple one-button operation. The variable-speed motor is controlled by a microprocessor to provide the wearer with the optimal amount of air. Audible and visual alarms signal low air flow or low battery voltage when the unit is used with a hood. The audio alarm can be heard even when noise levels are high. This respirator features automatic calibration, long battery life and a shower-proof design.