Enhance worker safety, complinace and traceability. Survives multiple 20 foot drops, waterproof and dustproof, wrapped in rubberized armor. Can be calibrated if it fails a bump test. Proprietary leak free H2S sensor for better stability in extreme conditions. Does not automatically shut down when 24 month clock runs out, typically lasts beyond. Maintenance-free with visual, audible and vibrating triple alarm, first alarm 10ppm second alarm 15ppm.