Why US31; No more paying to have water delivered, or wasting time replacing low-capacity pitcher filters and faucet filters, the US31 Under-Sink Water Filter provides up to 2000 Gal. directly from your tap at a fraction of the cost. This 3-stage filter system is designed for easy installation, low maintenance, and features a high-capacity sediment filter, a granular activated carbon (GAC) filter, and a carbon filter. The sediment filter protects and extends the life of your system by removing visible particles, while the GAC and carbon filters work together to eliminate harmful contaminants like chlorine, odor, and taste, providing you with bottled-quality water on demand.