The Hoffman simulator mounts to a bracket which is mounted somewhere near the front of a tank's turret. On the M1 Abrams it is clamped to the fume extractor,^{[citation needed]} while on recent variants of the Leopard 2 it is mounted on the frontal turret armor.^{[citation needed]} The system is manually loaded and fired electrically, with firing linked to the trigger of the tank's main gun.

The system is referred to as the "Simulator Tank Gunfire: Main Weapons Effect Signature" in US service, with the cartridges referred to as Simulator, Flash, Artillery M21.^[3]

Over the course of 20 years of service with the US Army, the Hoffman Device acquired a reputation for being prone to accidental discharges: while it is only supposed to fire when triggered electrically, there were numerous cases where static electricity or other local electrical fields resulted in uncommanded firing. A series of internal documents obtained by CBS News in 2003 included statements that "the ammunition is always unsafe" and saying many of the devices were "an accident waiting to happen."^[4]

In early 2004, modifications were made to Hoffman simulators to prevent uncommanded firing, and a notification was circulated stating that any unmodified devices found in stock should be destroyed.^[5]