Siphons and mixes liquid fertilizer as you water. Simplifies dilution by mixing at a rate of 16:1 (water to fertilizer). Unit attaches between garden hose and faucet with the suction tube placed in a pail of fertilizer solution. Excellent for seaweed/fish fertilizers. Widely used by commercial greenhouses and home gardeners. NOTE: Siphon action is related to water flow rate. Not for use with drip irrigation. Built-in backflow preventer. Requires a minimum of 35 psi for proper operation. Made in the USA.