This kit is not to be underestimated. Despite it being a 2 gallon (7.5 liters) reservoir, the included air pump is a powerhouse. This oversized pump can handle up to 5 gallons of air and will provide all the air you need. This package is perfect for filling up load-leveling air springs. If your truck has air springs without a compressor setup, this is the perfect compliment. Please note that if you use horns, you will still need an air valve kit to connect the system properly. Unlike some other air systems, HornAir kits come with 10 and 18 gauge wire, and a complete wiring kit including a fuse holder. This takes out the guess work on your end and makes sure your system is installed correctly. This kit is perfect for HornBlasters Shocker horns running at 150 PSI. Please Note: This HornAir system is not recommended for AirChime horns. Recommend to use at least a 4-gallon tank with larger scale train horns like the P3, P5, K3, and K5.