OVERGUARD S1

The smart helmet pod that connects your workforce.

A compact electronics pod that retrofits onto any EN 397 certified safety helmet in 30 seconds. No tools. No new helmets. Just clip it on and go live.

165gadded weight
30 secondfit time
View specifications →
Overguard S1 — product illustrationOverguard S1 safety sensor pod front-facing view with callout labelsSOSOVERGUARDStatus stripTeal · 9 LEDsLTE-M antenna4G · BLE 5.2SOS buttonChrome · deliberate pressUSB-C portFast chargeMagnetic dock4-pin pogo · fleetIP67 sealDust · waterproof6-axis IMUFall · impact · ML165g10–12h batteryIP6730s fit timeATEX Zone 2Overguard S1 — 85 × 55 × 28mm

Fits any EN 397 helmet.

Clip the S1 to any certified safety helmet in 30 seconds. No tools. No modifications. No new helmets required.

Overguard S1 fitted to safety helmetWhite EN 397 safety helmet shown in three-quarter rear view with the Overguard S1 sensor pod clipped to the rear bandOVERGUARDLIVEClips to any helmetEN 397 certified · 30 secondsLTE-M + 4GDirect cellular · no phoneStatus strip9 LEDs · real-time statusSOS buttonOne press · emergencyLive from power-onConnects in seconds

From box to live in minutes.

01
Clip to helmet
The S1 pod attaches to the rear stabiliser band of any EN 397 helmet. No tools needed.
02
Scan QR code
Supervisor scans the QR code on the pod using the Overguard app. Device is instantly provisioned to the platform.
03
Assign to worker
Assign the device to a worker from the workforce register. Worker identity, trade, and employer linked in seconds.
04
Go live
Device appears live on the site map. All sensors active. Safety monitoring begins.
SENSOR STACK

Every sensor. Every environment.

Motion & Safety
6-axis IMU (LSM6DSO)Fall detection — on-device MLImpact measurement (g-force)Man-down detectionTilt and orientation
Location & Positioning
GNSS: GPS + GLONASS + Galileo (u-blox M10)BLE 5.2 mesh (indoor positioning)Site beacon triangulation
Environmental
Temperature & humidity (ambient)Noise exposure (dB-A continuous)Air quality (PM2.5/PM10)Gas detection via BLE integration
OVERGUARD S2
Biometric
Heart rate monitoring (optical PPG)Skin temperatureFatigue scoring algorithmHydration indicators
Biometric monitoring requires individual consent. Available in the Overguard S2.
Communications
LTE-M / NB-IoT4G LTE fallbackBluetooth 5.2LoRaWANNFC provisioning
Processing & Storage
ARM Cortex-A application processorARM Cortex-M4 always-on safety core72h local data bufferOTA firmware updatesSigned firmware + rollback protection
TECHNICAL DIAGRAMS

Under the hood.

OVERGUARD S1 — EXPLODED VIEW
LTE-M antenna
Meander · embedded in shell
OVERGUARD
Polycarbonate shell
IP67 · Drop tested 2m
SOS button
Chrome ring · spring return
9-LED status arc
Flex-coupled to main PCB
nRF9160IMUGNSSPMIC
Main PCB
Nordic nRF9160 + nRF52840
6-axis IMU
Fall + impact detection
GNSS module
GPS + GLONASS + Galileo
USB-C connector
Fast charge · 11-pin
1800 mAh3.7V LiPo
1,800mAh LiPo
10–12h · PCM protected
Actual size: 85 × 55 × 28mm

Certified for the most demanding environments.

Every certification your site requires, built in from day one.

EN 397:2012+A1
EU Safety Helmets
Primary helmet certification
ANSI/ISEA Z89.1
US Head Protection
North American compliance
IP67
Ingress Protection
Dust-tight, 1m immersion
ATEX Zone 2
Explosive Atmospheres
Oil, gas, mining safe
CE + UKCA
Market Conformity
UK and EU sales compliance
MIL-STD-810H
Military Standard
Extreme environment tested
IN DEVELOPMENT

Introducing the Overguard S2.

The S1 is available for pilot deployment now. The S2 expands the sensor stack with native gas detection and biometric monitoring. Pilot clients get priority access.

OVERGUARD S2
Biometric monitoring
Heart rate, skin temperature, and fatigue scoring. Requires individual consent.
OVERGUARD S2
Native gas detection
O2, CO, H2S, and LEL detection integrated directly into the S2 pod.
OVERGUARD S2
UWB precision indoor
Sub-30cm accuracy for confined spaces and complex indoor environments.
OVERGUARD S2
Integrated camera
Optional clip-on camera for incident documentation.

Full technical specifications.

Physical
Dimensions85 × 55 × 28mm
Weight (pod only)165g
HousingPolycarbonate + TPU gasket
Colour optionsMatte black / Hi-vis yellow
Operating temperature-20°C to +60°C
Drop rating2 metres
Power
Battery capacity1,800mAh LiPo
Continuous operation10–12 hours (full sensor mode)
Extended mode14+ hours (reduced polling)
ChargingMagnetic pogo-pin dock + USB-C
Fast charge80% in 45 minutes
Battery monitoringState of charge reported to platform
Connectivity
PrimaryLTE-M / NB-IoT (embedded SIM)
Secondary4G LTE (high-bandwidth fallback)
LocalBluetooth 5.2
Remote sitesLoRaWAN (site gateway required)
ProvisioningNFC + QR code
Firmware updatesOTA (signed, rollback protected)
Location
Outdoor GNSSGPS + GLONASS + Galileo
IndoorBLE 5.2 mesh triangulation (anchor beacons)
Precision indoorUWB module (optional, <30cm accuracy)
Geofence processingOn-device edge compute
Position update rateEvery 5 seconds (configurable)
Processing
Safety processorARM Cortex-M4 (always-on)
Application processorARM Cortex-A
Local storage72 hours of full sensor data
Edge MLFall detection, fatigue indicators
OSFreeRTOS (safety core)
Certifications
Head protectionEN 397:2012+A1 / ANSI Z89.1
Ingress protectionIP67
Explosive atmosphereIECEx / ATEX Zone 2
Market conformityCE / UKCA
Environmental testingMIL-STD-810H

Ready to deploy the Overguard S1 on your site?

Pilot hardware available for confirmed pilot partners.

Request a pilot →