Rugged RFI-protected case designed for the most demanding environments. IP65 rated protection against dust and water. One button operation. Oversized (5" diagonal) backlit graphic display with automatic backlight. Super bright alarm lights visible in any direction. Field replaceable pump module. Black-box recorder with over 100 hours of storage. Four sensors. O2, LEL and up to three toxic channels using Biosystems' Duo-Tox two-channel CO/H2S sensor. Operating life: Alkaline pack: up to 24 hours. NiMH: up to 16 hours.