A four-tire inflation system does what the name says: it airs all four tires up — or down — at the same time, from one compressor, through four hoses.

The time saving is the obvious part. The equalizing is the better part. Because all four corners are plumbed together, they finish at the same pressure instead of you walking around the vehicle with a gauge and ending up with four slightly different numbers.

This is the universal version. The vehicle-specific kits ship with a bracket cut for one engine bay or bed. This one does not, so it goes on anything — a truck, an SUV, a trailer, a rig nobody makes a bracket for — as long as you can find somewhere to mount the control box and route the lines.

What you get: the Gen2 Air Delivery System control box with a 90 psi adjustable regulator, a 150 psi blow-off valve and a combined compressor and tire gauge; two inlet valves so you can run either a permanently mounted compressor or a portable one through an external Schrader fitting; pre-cut 3/8" DOT air line and 1/4" tubing with 90° Schrader valves and the Y and tee connectors already sized; eight quick-connect chucks with the Betty Bar tab; and a storage bag.

Why bother airing down: dropping pressure lengthens the tire's contact patch, and that is where traction in sand, rock and mud comes from. The catch is the other half — you have to put the air back before you touch pavement, because low pressure at highway speed builds heat, and heat is what destroys tires and unseats beads.

Fitment: universal. You supply the mounting location; everything else is in the box.

Compressor sold separately. Designed to work with ARB and VIAIR units.