Product Family : D1x. The explosion proof D1xB2XH1 is an auto-synchronizing Xenon Strobe warning light / beacon tested to UL1971. UL/cUL/ULC approved for Class I/II Div 1, Class I Zone 1/Zone 21 for gas and dust environments. The D1xB2XH2 is the brightest explosion proof Xenon Strobe warning light / beacon available for public mode fire alarm