HAL2 ETU

HAL²™ ETU (Specna Arms) is a modern electronic trigger unit for AEG replicas that combines a Hall-effect sensor, integrated safety sensors, and Bluetooth® Low Energy connectivity with the Specna Link™ mobile app. It is designed to deliver maximum trigger sensitivity, fast response time, and full protection of the replica’s drive system against damage.

Main concept and design

The core of HAL² is a magnetic Hall-effect trigger sensor that measures the trigger’s position without mechanical contact. This makes the system highly resistant to dirt and light interference while offering extreme precision (up to 500 calibration points). HAL² is designed as a “widget” compatible with most standard mechanical triggers, allowing the user to choose from different trigger styles and shapes according to preference.

What does HAL² ETU offer?

Trigger sensitivity adjustment:
Fine-tune sensitivity with up to 500 levels for precise trigger response.
Pre-cocking (piston pre-tension):
Allows the piston to stay pre-cocked for faster response after pulling the trigger.
Selectable firing modes:
SINGLE, BINARY, SERIAL, or AUTO — assignable to each selector position.
Burst length configuration:
Adjustable number of rounds per burst (2/3/etc.).
Rate of Fire control (RoF):
Option to limit or adjust desired rate of fire.
Battery protection:
Automatic detection of LiPo/Li-Ion undervoltage and active deep discharge protection.
Magazine simulation:
Simulates magazine behavior and allows ammo count management.
Real-time battery status:
Continuously displays the current battery level in the app.
Telemetry and monitoring:
Collects detailed operational data from the replica and displays them in the app.
Fault detection:
Built-in sensors monitor operating conditions and automatically stop operation in case of anomalies.

How HAL² differs from the first generation (HAL 1)

Bluetooth® Low Energy:
HAL² includes a BLE module for wireless communication with the mobile app — HAL 1 lacked this feature.
Higher precision and resolution:
HAL² provides up to 500 adjustment points, whereas older HAL units had lower resolution.
Enhanced telemetry and protection:
HAL² integrates additional sensors for replica monitoring and advanced protection of the battery and drivetrain.
Real-time user configuration:
Through the app, users can change settings “on the fly” and save multiple profiles — HAL 1 only allowed limited manual adjustment.

Specna Link™ app — how it works

Specna Link™ is the official mobile app (iOS version and Android version) that communicates with HAL² via Bluetooth® Low Energy. The app is designed to be intuitive and provides full configuration and diagnostics of the unit.