When installed inside Model MS-XPE-32/US-XPE-32 enclosure, Mini-/Micro-Screen light curtains in 20, 24, and 28 in. versions won''t ignite flammable gases, liquids, or dust. Cast-aluminum box with machined aluminum cover accepts emitter or receiver; drilled and tapped holes ease mounting of hardware. Conduit and fittings enter through 3/4 in. NPSM access at bottom.