These models are 1 hour fire rated at 1250º F. They have 1 1/2 inch chrome plated solid steal bocking bolts. built with drill/balistic resistant armored hard plate to protect lock. The walls are made of two layers of fireboard totaling 1" thickness. The door consists of 3 layers of fireboarding totaling 1 1/2 " thickness. Door also has 1/4" solid steel plate for pry bar resistance.