The VPS-1500A is a UL Listed Vapor-Phase Corrosion Inhibitor (VpCI®) Delivery System for Dry Pipe & Pre-Action Fire Sprinkler Systems. The VPS-1500A has a corrosion prevention Fill Capacity of up to 1,500 gallons (the Largest Riser) and a Total Capacity of up to 6,000 gallons for up to 4 individual systems.