The chamber and hardware are Type 304 stainless steel for dependable long life. The Minipure is electropolished and passivated for an attractive finish and dependable service. Exclusive, patented Easy-Off Retainer Cap enables effortless lamp replacement without shut-down of water pressure or drainage of tank. No tools are required. The fused quartz sleeve ensures optimum lamp output at normal potable water temperatures. An LED on the transformer provides visual indication of germicidal lamp operation.