Ideal Soaker Hose water volume is 1 gpm per 100 ft. This kit gets threaded inline prior to your soaker hose system to meter the flow and pressure. Accurate with pressures from 5-90 psi. Adaptors included to work with both 1/2"FPT and garden hose thread. Please state 1, 2, 3, 4, or 5 gpm when ordering. (This kit is not pictured, but it can be used with soaker hose at left.)