Posted by Daniel @ ArmsUnlimited on 13th Dec 2025

Flashbangs: Diversionary Devices in Law Enforcement

Flashbangs, also known as stun grenades or noise-flash diversionary devices (NFDDs), are less-lethal tools designed to temporarily disorient suspects through an intense combination of light, sound, and pressure. They produce a blinding flash (typically 6-8 million candela) and a deafening bang (around 170-180 dB), causing temporary flash blindness, deafness, tinnitus, and inner ear disturbance. Modern designs are non-fragmenting and non-bursting to minimize shrapnel risks, relying on deflagration (rapid burning) rather than high-explosive detonation.
When and How They Are Used: Law enforcement deploys flashbangs primarily during high-risk operations where surprise and distraction provide a tactical advantage, allowing officers to gain control without immediate resort to lethal force. Common scenarios include:
  • Dynamic room entries during search warrants or high-risk arrests.
  • Hostage rescues and barricaded suspect situations.
  • Tactical assaults on fortified positions.
Deployment is typically hand-thrown into a room or area just prior to entry, with a standard 1.5-second delay fuze. Officers throw the device through a door, window, or breach point, then immediately follow with entry to capitalize on the 1-3 seconds of disorientation. They are especially valuable in scenarios requiring rapid neutralization of threats while minimizing harm to hostages or bystanders.
Fire Risk Associated with Flashbangs: Despite their less-lethal classification, flashbangs carry a significant fire hazard due to the pyrotechnic composition that generates intense heat and sparks during deflagration. Incidents have occurred where devices ignited flammable materials, leading to house fires, severe burns (including to infants in notable cases), or even fatalities from smoke inhalation or heart attacks triggered by the event. The risk increases in cluttered environments, near bedding, clothing, or accelerants. Proper risk assessment and pre-deployment intelligence are critical to mitigate this danger, and some agencies stage fire suppression resources during operations involving flashbangs.
CTS Variants Available from Arms Unlimited: Combined Tactical Systems (CTS) is a leading manufacturer of reliable, high-performance flashbangs, offering a range of single- and multi-bang options tailored to different tactical needs. These aluminum or steel-bodied devices feature non-fragmenting designs and superior fuze reliability. Key variants include: All CTS flashbangs are accessible through authorized distributors like Arms Unlimited.
Special Considerations for Multi-Bang Devices: While multi-bang variants (double, 3, 6, or 9 bang) excel in providing sustained disorientation—resetting auditory and visual recovery with each blast—they should be used with caution in hostage situations. The repeated bangs can mimic incoming gunfire, potentially causing an armed suspect to believe they are under attack. This may provoke return fire or harm to hostages in panic. In such delicate scenarios, single-bang devices are preferred to minimize escalation risks while still achieving effective diversion.
Flashbangs remain a cornerstone of tactical operations, balancing effectiveness with less-lethal intent, but their use demands rigorous training, situational awareness, and adherence to policy to ensure safety for all involved.
40mm Aerial Flashbangs:
In addition to hand-thrown diversionary devices, law enforcement agencies utilize launched variants such as 40mm aerial flashbangs for extended-range deployment. These pyrotechnic rounds are fired from 40mm launchers and detonate at a predetermined distance, producing an intense flash (minimum 6 million candela) and loud report (165-175 dB average) without fragmentation.
Combined Tactical Systems (CTS) offers the Model 4090 series aerial flashbang, available in burst distance options (50, 100, 200, or 300 meters, with the 50-meter variant being most common). This single-use round provides a safe, overhead diversionary effect for outdoor scenarios. Details and purchasing for law enforcement agencies are available at https://armsunlimited.com/cts-4090-40mm-aerial-flash-bang/.
Primary uses include crowd control during riots or large gatherings, where the round is fired high above the crowd to create widespread sensory overload, encouraging dispersal, determining intent, or issuing warnings without direct impact. Exercise caution when firing above crowds and be aware of the possibility of fragmentation.
Aerial flashbangs can also serve as remotely launched diversionary devices in tactical operations, such as detonating near windows in multi-story buildings to disorient occupants prior to entry—though strict protocols prohibit firing directly into structures to avoid fire risks or unintended indoor detonation.
As with all flashbangs, aerial variants carry pyrotechnic fire hazards and require elevation (at least 50 feet/15 meters above subjects) for safe use. They provide officers with a stand-off capability to achieve distraction at distance, supporting less-lethal resolution in dynamic environments.