Mul-T-Lock Knob Lockset with MUL-T-LOCK MTL800 Cylinder Backset:2 3/8" The Black Hawk series features

The Black Hawk series features a 90 minute fire rating with an intumescent door seal that swells to seal the door when exposed to fire and heat and will outlast the standard house fire

and rotating disc cutters and they were still unsuccessful

Re-locker for added burglary protection

The Hunter series features a 45 minute fire rating and will outlast the standard house fire

Mul-T-Lock Knob Lockset with MUL-T-LOCK MTL800 Cylinder Backset:2 3/8" The Black Hawk series featuresPart No. : MO 800 KLxxUx Cylindrical locksets are designed to provide superior door protection with uncompromised key control. Each Lockset is fitted with a MUL T LOCK Key In Knob and available in a Knob Design or ADA (America Disabilities Act) Compliant Lever Design. Various functions available for just about any need. Like all MUL T LOCK Products the cylinder is protected by MUL T LOCK's Limited Lifetime Mechanical Warranty. Features: ANSI Grade 2