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Small rectangular adapter, 7.9 by 5.5 mm female port to large square USB male plug, matte black finish

eForChina

eForChina 7.9x5.5mm Female to Big Square USB First Gen Male Power Adapter

SKU CH-51X1-C96JA

Converts a 7.9x5.5mm power jack to a first-generation big-square USB male plug for ThinkPad, ThinkBook and Xiaoxin laptops

  • Changer TypePower Adapter
  • Connects legacy ThinkPad chargers via 7.9x5.5mm female to big square USB first-gen male
  • Compact adapter fits in any laptop bag for travel-ready power conversion
  • New condition ensures reliable contact without worn-pin failures
  • Passive gender changer requires no drivers or external power to operate
  • Direct replacement for lost or damaged proprietary power tips

Power adapter for legacy ThinkPad chargers

This 7.9x5.5 mm female to big-square male adapter lets you connect an older rectangular ThinkPad power tip to a device that expects the larger square first-generation connector. It is intended for owners of ThinkPad, ThinkBook or Xiaoxin laptops who need to reuse an existing charger with the smaller round tip. The passive design requires no drivers or configuration.

Check your charger tip and laptop port

Verify that the original charger ends in a 7.9 mm by 5.5 mm round plug and that the laptop power socket matches the big square first-generation male interface. Polarity and voltage are not altered by the adapter so both power supplies must already share the same electrical specification. No driver installation or software setup is involved.

Compact passive build for daily carry

The moulded plastic housing is small and lightweight, adding minimal bulk to a laptop bag. Because there are no moving parts or active electronics, the connection stays reliable through repeated plugging and unplugging. The rigid gender-changer layout keeps the two connectors aligned without a cable that could snag or fray.

Highlights

  • Connects legacy ThinkPad chargers via 7.9x5.5mm female to big square USB first-gen male
  • Compact adapter fits in any laptop bag for travel-ready power conversion
  • New condition ensures reliable contact without worn-pin failures
  • Passive gender changer requires no drivers or external power to operate
  • Direct replacement for lost or damaged proprietary power tips

Specifications

Changer TypePower Adapter

Questions about this item

What connectors does the eForChina adapter join?

It connects a 7.9x5.5 mm female barrel jack to a large square first-generation USB male plug.

Which ThinkPad models use the large square first-generation USB power tip?

Older ThinkPad and ThinkBook laptops that charge through the proprietary square USB-style connector rather than USB-C or slim-tip barrels.

Does the adapter change the voltage or current from the charger?

No, it is a passive gender changer so the charger must already supply the correct voltage and current for the laptop.

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