The MIFAB's MPFR fire rated access door is approved by Underwriters Laboratories Inc., for 1 1/2 hours, "B" label in walls and is approved by Warnock Hersey for 2 hours in ceilings and 3 hours in walls. It meets ANSI-UL 10B standards. Material - MPFR Series is 16 gage satin coat steel front door with 20 gage backliner and 16 gage satin coat steel frame.  Finish - Satin coat steel doors have a primed white finish. Door - Flush to frame. Self-closing. Can be opened from the inside or back of the door with MIFAB's unique thumb turn latch. Frame - Four piece welded frame with masonry mounting straps. Hinge - Concealed pivot pins. Spring - Heavy duty. An extra spring is provided with every door greater than 14" x 14" (356 x 356) for ceiling installation. Both springs must be attached to the door to ensure that the door will close when installed in the ceiling. Latch - Standard - Flush mounted, interchangeable turn ring operator and key operator latch. Optional - cylinder key lock. All of MIFAB's cylinder key locks are keyed alike. Fire Rating - Underwriters Laboratories "B" label. 1 1/2 hours for walls. Warnock Hersey: 1 hour combustible ceilings and walls, 2 hour non-combustible ceilings, and 3 hour non-combustible walls. Ceiling fire ratings are up to and including the 24" x 36" (610 x 914) size. Insulation - Roxul Rockboard 80. 2" (50) thick and fire retardant.