66 Block, Solid-State, UL Listed Secondary Protector, 160mA PTC, 2 LEDs to Indicate Protection and Ground OK. (27V / 39V / 75V / 235V Clamping).
Applications: Provides second layer of protection for Digital lines behind UL Listed Primary Protection.
(*Made in USA of U.S. and imported parts* )

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  • Agency ApprovaL UL 497A (Secondary)
  • LED Indicators / Sneak Current Protection Yes
  • Grounding Requirements Field installed solid copper wire
    for Secondary 1-6 pairs 14 AWG
    for Secondary 7-25 pairs 6 AWG
  • Recommended Grounding Impedance <0.5 Ohm
  • PTC Rating 160mA (8-10 Ohms)
  • Applications Data / Voice / Fax / Modem lines
  • Width / Height / Depth / Weight 1.88” / 2.62” / 0.38” / 0.04 lbs
  • Product Warranty Lifetime


  • Signal Perfect Circuitry Yes
  • Auto-Resettable Yes
  • Clamping Leve 27V, 39V, 75V, 235V
  • Response Time 1-5 Nanoseconds
  • Capacitance <50pF
  • Suppression Modes Metallic & Longitudinal
  • Wires Protected 2-wires, 1-pair
  • Termination Type 66 type M Blocks


  • Dual Indicator Lights Protection OK and Ground Connection OK
  • Solid-state Protection Provides the fastest response
  • Single Pair Protection Scale the protection to the system size. Protect only the lines requiring protection
  • Streamlined Installation Eliminate redundant cross-connects by adding protection directly at the 66 Block. Press fit protectors to the block and attach the ground bar to the protectors. A Screw Ground Lug also is required. (MGBSGL-1)
  • Sneak Current Protection Protects against fires caused by overloads and power crosses
  • Cost Savings Eliminate expensive five-pin blocks and use economical 66 Blocks
  • Optimum Protection Available in a number of voltage ratings to match system operating voltages
  • Ideal for Retrofit Applications Just remove the bridging clips from the block & replace them with the UltraLinx Protector, add the ground connection and the pair is protected
  • Lifetime Product Warranty This surge protector shall be free of any defects in design, materials, or workmanship, or ITW Linx will repair or replace the defective product