Milesight GS301 LoRaWAN® Bathroom Odor (NH3 & H2S), Temperature & Humidity Sensor (EU868)

Milesight GS301 LoRaWAN® Bathroom Odor (NH3 & H2S), Temperature & Humidity Sensor (EU868)

• Detect NH₃ & H₂S with Higher Accuracy
• Built-in Buzzer & Traffic Light Status Indicator for Alarming
• Up to 3 Years Battery Life
• Support LoRaWAN® & Milesight D2D Simultaneously
• Milesight D2D with Communication Latency to < 1 Sec

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Product Description

The Milesight GS301 is a LoRaWAN® Bathroom Odor Detector designed to enhance the air quality and hygiene in bathroom environments. This compact and easy-to-install device is equipped with damp-proof coating, allowing it to function effectively in various bathroom conditions. It integrates 4-in-1 sensors with high sensitivity, including ammonia (NH₃), hydrogen sulfide (H₂S), temperature, and humidity sensors.

Key Features

  • Ammonia and Hydrogen Sulfide Detection: Uses electrochemical principles to detect NH₃ and H₂S gases with high accuracy (±5%).
  • Temperature and Humidity Monitoring: Provides real-time environmental data for comprehensive bathroom management.
  • LoRaWAN® and Milesight D2D Support: Offers dual communication protocols for flexibility in deployment and control.
  • Effective Alarm System: Includes traffic lights indicator, built-in buzzer, and uplink data packets to alert when gas concentrations reach threshold levels.
  • HVAC System Integration: Can automatically adjust ventilation based on detected gas concentrations.
  • Extended Battery Life: Powered by 4 x 4000 mAh ER18505 Li-SOCl₂ batteries, ensuring up to 3 years of service life.
  • Smart Restroom Solution Compatibility: Part of Milesight's Smart Restroom Solution, providing IoT insights for better cleanliness and hygiene.
  • Installation: Wall-mounted design for easy and convenient installation.
  • NFC Configuration: Allows for easy device configuration via a mobile app.


  • Smart Restrooms: Ideal for public and private bathrooms to monitor and manage air quality and hygiene.
  • Environmental Monitoring: Useful in various indoor environments where air quality is a concern.

The Milesight GS301 is a practical and innovative solution for improving air quality in bathrooms, combining advanced sensor technology with LoRaWAN® capabilities for efficient and remote monitoring​.

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Wireless Transmission
Protocol LoRaWAN® , Milesight D2D
Frequency CN470/IN865/RU864/EU868/US915/AU915/KR920/AS923-1&2&3&4
Tx Power 16 dBm (868 MHz)/19 dBm (470 MHz)/22 dBm (915 MHz)
Sensitivity -137dBm
Mode OTAA/ABP Class A
Ammonia (NH3)
Detection Principle Solid Polymer Electrochemical
Range 0 ~ 10 ppm
Accuracy ± 5% (-40 - 35°C)
Long-term Stability < 1 % accuracy drift per month
Resolution 0.01 ppm
Hydrogen Sulfide (H2S)
Detection Principle Solid Polymer Electrochemical
Range 0 ~ 5 ppm
Accuracy ± 5% (-40 - 35°C)
Long-term Stability < 1 % accuracy drift per month
Resolution 0.01 ppm
Range -40 - 85°C
Accuracy ± 0.2°C
Resolution 0.01°C
Range 0 - 100%RH
Accuracy ± 2%
Resolution 0.5%RH
LED& Buzzer 1 × Status/Alarm Indicator + 1 × Buzzer
Button 1 × Reset/Reboot Button
Configuration Mobile App via NFC
Advanced Feature Milesight D2D Controller
Physical Characteristics
Power Supply 4 x 4000 mAh ER18505 Li-SOCl2 Replaceable Batteries
Sensor Life > 3 Years
Battery Life Around 3 Years (10 min interval)
Operating Temperature -40°C - 55°C
Relative Humidity 0% - 95% (non-condensing)
Ingress Protection IP30
Dimension 120 × 85 × 32.5 mm (4.72 × 3.35 × 1.28 in)
Material & Color PC+ABS (Flame Retardant), White
Installation Wall Mounting

Shipping Policy

We provide worldwide shipping using reliable tracked
shipping services.

Local Shipments within Cyprus

Shipments in Cyprus are performed usually with ACS Courrier
or AKIS Express. In some cases, we might deliver the products ourselves. A pick-up
option from our locations is also available.

International Shipments

International shipments are performed using Express Airway
Shipping Services. We are currently shipping orders with TNT Express and FedEX.
As soon as your shipment is dispatched you will receive the shipment confirmation
including the shipment tracking number which you can use to track your order
from the shipment provider website.

We dispatch orders within 1-3 workdays after the day of the
order placement. 

General Return Policy

We have a 30-day return policy, which means you have 30 days
after receiving your item to request a return.

To be eligible for a return, your item must be in the same
condition that you received it, unworn or unused, with tags, and in its
original packaging. You’ll also need the receipt or proof of purchase.

To start a return, you can contact us at If
your return is accepted, we’ll send you a return shipping label, as well as
instructions on how and where to send your package. Items sent back to us
without first requesting a return will not be accepted.

For any further information, help and support regarding the
shipping and/or return process you can contact us at:

  • Email:
  • Telephone: +357 22 282828