MSA Altair 4XR Gas monitor 10178587

The waterproof and shock rating on the 4XR has been improved compared to the MSA Altair 4X. 

Gas monitors are not only expensive to buy, but also expensive to run. Every 6 months you are required to have the unit calibrated at a cost, plus most units come only with a 2 year warranty, so when a sensor expires you are up for the cost to replace it. This gas monitor from MSA  comes with a 5 year warranty covering all sensors.

If you are making a purchase for long term use, then this should be your choice. Some companies insist on daily bump testing. The Altair 4XR actually indicates on the main screen that the unit has been bumped within the last 24 hours. Plus the Altair is waterproof and dustproof.