Your alarm detects. LIMA SHIELD acts.
Keep your alarm: it does its job very well. It detects, it sounds, it alerts. The real question is what happens next: a burglary lasts 6 to 12 minutes on average, while your alarm's job is done within a few seconds. This page compares the two roles and shows how they fit together.
“I was a municipal police officer. Dozens of times I arrived after an alarm had gone off: it had done its job, and the intruder had had time to do theirs. What was missing was something that acts while it is happening.” Cédric Fontaine, founder of Lima Groupe
Comparison checked in September 2026.
You are not here by chance: you have already invested in your security, and there is still a nagging concern nobody really puts into words. Here it is, as we hear it from most homes and shops that are already equipped.
None of these problems is your alarm's fault: they arise because it works alone. It has no means of acting.
As soon as the intrusion is confirmed, LIMA SHIELD warns the intruder with a sequence of beeps, then floods the area with a sound of 86 to 138 decibels that makes it unbearable and triggers a flight reflex. The intrusion is cut short instead of running its course.
Local detection with no network needed, tamper protection if someone tries to tear it off, backup 4G if the router is cut or jammed, an internal battery lasting one month, up to 3 months with secondary batteries: a power cut, jamming or sabotage of the main alarm will not stop it.
Connects to most professional systems via dry contact or radio relay: it uses your existing detectors and cameras. And if your alarm is a wireless consumer system, it works fully independently with its own detection.
If you remember only one thing, make it this: these two systems do not act at the same point in an intrusion. One works before it starts and when it is detected, the other while it is under way. The full details follow.
Here are the two systems side by side, on the criteria that truly decide what happens between the siren going off and someone arriving on site. None of these criteria is theoretical: they are the ones our customers mention when they describe their own intrusion.
| Conventional alarm | LIMA SHIELD | |
|---|---|---|
| Role | Passive protection: observe and alert. | Active protection: act during the intrusion. |
| During the intrusion | The siren sounds, the intruder keeps searching. | The room becomes unbearable within seconds. |
| Against a prepared intruder | A siren they know and expect. | A modulated, unpredictable signal the brain cannot get used to. |
| False alarm | The siren goes off for nothing, neighbours disturbed, credibility damaged. | Warning and a 10-second delay before any emission: time to deactivate by code, badge or app. |
| Jamming and sabotage | Wireless consumer systems are vulnerable to them. | Local detection, tamper protection against removal, backup 4G. |
| Power cut | Varies by installation. | 1 month of battery life, up to 3 months with secondary batteries. |
| Both together | They complement each other: dry contact or radio relay. The alarm detects, LIMA SHIELD acts. | |
We would rather help you decide than convince you. Here, honestly, are the situations in which LIMA SHIELD makes a difference, and those in which it is not your priority right now.
For the vast majority of homes and shops that are already equipped, the answer is layering: your alarm keeps detection and alerting, LIMA SHIELD adds action.
Everyone in France knows what an alarm sounds like, burglars better than anyone. The LIMA SHIELD signal varies several times per second, in frequency and intensity: the brain can neither predict it nor get used to it, and staying in the area becomes physically unbearable.
An organised intruder cuts the power or jams the wireless before going in. LIMA SHIELD detects locally, protects itself if someone tries to tear it off, switches to its battery and its 4G, and alerts you anyway. The active system keeps going when everything else fails.
Warning beeps, a 10-second delay, deactivation by code, badge or app: the system gives you time to cancel. And if it does go off: no substance, no residue, everything is back to normal immediately.
Perimeter detection from the alarm, alerting and alarm verification, then action in the zone: this is the architecture security professionals recommend, and the one public authorities are already promoting: the French State subsidises up to €10,000 towards equipping tobacconists with active protection devices.
A French acoustic deterrent device, winner of the Audience Award at the Nuit de la Sécurité Globale (Républik Group). When an intrusion is confirmed, it warns the intruder with a sequence of beeps, then emits a sound of 86 to 138 decibels, calibrated to the 2 to 5 kHz band where human hearing is most sensitive. Staying on site becomes impossible: no contact, no substance, no confrontation.
Behind the unit: a French startup, co-founders from the army and the police, engineers from the defence and acoustics sectors, some of them formerly at Dassault, nearly €1 million in research and development, prototypes built in Strasbourg, and compliance with European CE standards.
“It is not simply an alarm that sounds a warning; it is a true ‘sound shield’, which aims to drive the individual out by the sheer force of sound.” Yoann Le Meur, Medium
Jewellers, tobacconists, luxury boutiques, warehouses, town halls and police stations already feature among our first customers and pre-orders.
Depending on the extent of the loss, the total cost of a burglary can range from around €2,000 to €95,000: stolen goods, damage, repairs, insurance excess and the impact on your insurance policy. LIMA SHIELD costs €2,500 excl. VAT, once, with no subscription: around 68 cents a day over its 10-year lifespan. And we carry the long-term risk: 2-year manufacturer's warranty, battery excluded.
With most professional systems on the market, yes: the wired dry-contact connection is universal, and the radio relay goes through your brand's compatible modules. With a fully wireless consumer alarm, the honest answer is different: it is better to run it independently, with its own detection, rather than make it depend on a system that can be jammed.
No, and it is not designed to. Remote monitoring raises the alarm and sends people out; LIMA SHIELD acts on site, in the minutes before anyone has arrived. The two levels of protection work together, and LIMA SHIELD itself works without a subscription.
The sensors are designed to distinguish small body sizes and low-level movement. Before any emission: warning beeps and a 10-second delay, time to deactivate by code, badge or app. And a brief accidental activation causes at most temporary discomfort: no substance, nothing to clean up.
Yes. For indoor use, no French law or regulation known to date caps the power of an acoustic deterrent device: the 115 dB limit concerns outdoor sirens, a standards category to which LIMA SHIELD does not belong. It is CE compliant, and in the event of an intrusion its use falls within the lawful defence of property (article 122-5 of the French Code pénal), with warning, delay and automatic shut-off.
Today: the alarm sounds, you wake up, and what happens next is up to you. With LIMA SHIELD: the intrusion is confirmed, the warning goes out, then the area becomes unbearable and the intruder flees, while you stay upstairs with your family. Your system puts up the barrier, not you.
LIMA SHIELD installs in 5 to 10 minutes, alongside your existing system or on its own. It is produced in limited runs, and is regularly out of stock.
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