Response is seen on LED plus an audible tone is heard. Features include: Standard cable lengths: 300´ and 500´. Small 3/8Þ dia. brass electrode is field replaceable. Plastic reel-type spool for lowering cable and electrode assembly. Reel is mounted on a tubular aluminum stand. High tensile strength cable (approx. 300 lbs.) with plastic insulating jacket. Two lead cable for use in uncased test holes or uncased wells in rock. English graduations every five feet. Self-contained 9V battery power supply – no danger of shock from an outside power supply. Battery test. Standard brass electrode. Reel handles are shaped to fit your hands. Accurate to ±1% of reading. Each WLT Water Level Indicator is supplied with a 9V battery, six oil bags, and instructions.