Altair 4X is a multi-gas detector, measuring up to four gases simultaneously: CH₄, O₂, H₂S, and CO, as well as combustible gases and vapors.
The MSA XCell sensors' service period is twice as long as the industry average and the sensors have been developed using ASIC technology patented by MSA.  Because of this, the manufacturer's warranty for the gas detectors is for three years. 
The device may display toxic gas in mg/m³.
Methane calibration – by default. Thermocatalytic sensor can be calibrated equally well with propane, pentane, hydrogen, nonane, and butane.

Specifications:

Weight: 222 g.
Dimensions: 112×76×35 mm.
Alarm: flashing (360°), audible, vibrating.
Environment temperature range: –40…+50°C.
Uninterrupted run time: 24 hours (at room temperature).
Battery charging time: less than 4 hours.
Data log: 500 recent events / 50 hours.
Dust/water protection class: IP 67.
Explosion proof: 0 Ex ia IIC T4 X or 1 Ex diamb or 1 Ex diamb IIC T4 X and PO EX ia I X.

Advantages:

• Shock-resistant rubber housing (allows the device to withstand a fall from 6 meters onto a concrete floor), with a compact and ergonomic design.
• Immobility function Motion Alert.
• Manual alarm function Instant Alert.
• IR connection with PC.
• May be ordered in a photo luminescent housing.
• Compatible with Galaxy GX2 automated test system.
• 3 year warranty period (electronics, sensors, battery).

GOST R 52350.7-2005 (IEC 60079-7:2006)
GOST R 52350.11-2005 (IEC 60079-11:2006)
GOST R 52350.18-2006 (IEC 60079-18:2004)
GOST R IEC 60079-0-2007
GOST R IEC 60079-1-2008
GOST 22782.3-77

The service period (24 months) for these devices shall commence immediately after calibration.