Portable compressors with automatic shutoff come into play when moving from tire to tire, and when checking tire pressure in the middle of a tire fill. A typical portable compressor must be turned off between tire fills, and anytime you want to check tire pressure. If you aren’t near the compressor, this can turn into running laps back and forth to the portable compressor to turn the unit on and off. Automatic portables do not work in this fashion and will save you time & effort to get tires inflated quickly. Please Note: The air hose supplied with this kit may become brittle from prolonged exposure to UV/sunlight. – Stow when not in use. Never allow the hose to come into contact with the head of the compressor during use (melting hazard). The use of the included air hose is not recommende.