Simpson’s Model 8455 Line Loop tester detects line shorts, opens and multiple ringers, DC voltages and loop resistance. It can measure DC voltage up to 100 volts and loop resistance to 2 megohms. A front panel “reverse polarity” switch allows changing polarity positions quicker and easier than manually switching test leads when making line checks. This switch is field-replaceable, enabling your loop tester to be operational at all times without costly shop repairs. The compact durable construction of this tester ensures continued accuracy even under the most rugged field conditions.

• Field Replaceable Switches - Allows operator to get back to the job quickly
  with less downtime. The replacement toggles or push buttons can be kept in
  the truck and replaced on site, keeping the unit in service, at all times.
• Designed for Telecom Applications - Accurately checks line shorts, opens
  and multiple ringers.
• Wide Measuring Range - Measures DC voltage 0-100V and resistance R x 1,
  R ÷ 10.
• Shorter Testing Time - Polarity toggle switch eliminates manually switching
  test leads when conducting line checks.
• Rugged for Field Use - Durable, compact (5-1/2" x 2-3/8") construction
  makes it portable, easy to store and rugged.
• Accurate, Finer Readings - 0-100 points scale calibration yields accurate
  readings.