Greenlee 521A Wire and Valve Locator High power transmitter offers extended long range and allows use on higher resistance wire paths Adjustable transmit power allows you to select the best signal for maximum performance Receiver provides adjustable loudspeaker audio, headset audio and visual indications of signal strength Long-nose receiver wand makes it easy for you to move along quickly to locate even the longest wire path Valve solenoid hotspot signal makes pinpointing valves easy and rugged headphones block ambient noise