Perform-Max™ Model #920 Above Ground In-Line Feeder : For pools up to 25,000 gallons and large spas. 7-pound capacity. More Performance! Perform-Max™ Feeders bring you the best in bulk chlorine or bromine feeding. No other bulk feeder offers erosion technology with exact metering capabilities. The Perform-Max™ Feeders are the only feeders with the patented Performance Valve™ that performs on cue, responding accurately to each adjustment in its wide range of settings. More Technology! The Performance Valve allows water to continuously erode only the bottom layer of chemical. When a small area of chemical is eroded, you can maintain output much easier than when an entire chemical supply gets wet (like in soaker feeders). More Options! Perform-Max™ Feeders can be used with chlorine or bromine - pucks, tablets or sticks - holding from 7 to 10 pounds of chemical. With 3 models to choose from, ther is a Perform-Max™ for you whether your pool is 10,000 or 50,000 gallons. No More Worries! Perform-Max™ Feeders maintain proper residual for any size pool, any weather conditions, any number of swimmers. The Performance Valve's wide range of settings gives you more control without over chlorinating.