It is necessary to use TRE Diff breather kit if you wish to take your vehicle through water above the axle height at any time. It allows your diffs, transfer case and gearbox to breathe by relocating the breather to a higher point on vehicle and stopping the affect of water being sucked into diff housings and gearboxes.
 
Working temperature: -20℃ - 120℃
Customizable tubes that can work at -40℃