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Silver grey zinc alloy magnetic reed switch pair with 50cm cables, screw mount, 105mm long

Unique-Bargains

Unique-Bargains OC-55 NC magnetic reed alarm 40-50mm 0.5A 100V 50cm

SKU CH-DFZH-NBR81 MPN OC-55

Normally closed magnetic reed switch activates alarms when doors or windows open beyond 40 to 50mm

  • Product typeSurveillance - Home Safety & Security
  • Detects door movement up to 50 mm away
  • Normally closed circuit opens when magnet separates
  • Switches up to .5 A at 100 V DC
  • Zinc alloy housing with stainless steel pipe for durability
  • 50 cm UL 1007 22 AWG leads simplify wiring

Magnetic Reed Switch for Alarm Systems

The Unique-Bargains OC-55 is a normally closed magnetic reed switch designed for security alarm circuits on doors, windows, rolling gates and garage doors. It suits installers and DIY users who need a simple contact sensor that closes the circuit when the magnet is within roughly 40-50mm and opens it when separated.

Screw Surface Mount with 50cm Leads

Each unit includes a zinc alloy housing and a stainless steel pipe that mount with screws through 5.33mm holes. The 1007UL#22AWG wires run 50cm from each component, giving enough length for typical frame-to-door runs. Misalignment beyond the 40-50mm actuation gap is the usual cause of false opens, so verify the magnet sits squarely opposite the reed before final tightening.

Rated for Continuous 0.5A at DC100V

The contact handles a maximum of 0.5A and 10W at DC100V, so it remains stable under sustained alarm-loop current rather than only brief pulses. The normally closed logic means the circuit stays conductive while the door is shut, and any sustained separation — whether from intrusion or a loose magnet — breaks the loop and triggers the panel.

How it compares

Measured against everything we stock in Alarm Kits & Motion Sensors, at today’s prices. Recalculated every night.

Price $9.99
Cheaper than about 93% of the 180 comparable items (median $30.99).

Specifications

Product
Brand nameUnique Bargains
Product typeSurveillance - Home Safety & Security

Questions about this item

How do I confirm the OC-55 reed switch is working after wiring it to my alarm panel?

With the magnet paired, the circuit is closed and the alarm input shows continuity; separate the magnet beyond 40-50mm and the circuit opens, removing continuity.

What comes in the box and what extra parts are needed to mount the OC-55?

The switch and magnet with 50cm 1007UL#22AWG leads are included; you must supply mounting screws for the 5.33mm holes and any alarm cable to extend the wiring.

Which contact type suits a zone that must stay closed while the door is shut?

The OC-55 is Normally Closed, so the circuit conducts when the magnet is within 40-50mm and breaks when the door opens — ideal for that zone logic.

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