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CEL-FI DUO+ Signal Booster for Verizon 4G LTE Data and VoLTE Calls [Discontinued]



The CEL-FI DUO+ for Verizon LTE is a great option when you need only need to boost Verizon 4G LTE signal in a home or office, but aren't able to mount an antenna outside. The two units connect wireless, so there's no need to run any cables, and setup takes just a few minutes. The CEL-FI DUO+ falls under a different FCC class than multi-carrier boosters, so it can boost up to 100 db of gain, compared to the 72 db that multi-carrier boosters are limited to, resulting in significantly more indoor coverage for Verizon LTE.

Why the CEL-FI DUO+?

  • More boosting power than multi-carrier boosters for maximum coverage.
  • CEL-FI WAVE smartphone app makes it easy to check on the health of the system and troubleshoot any issues.
  • No outside antenna required.
  • Works wirelessly. No physical connection to your phone required.
  • Supports multiple phones at the same time.
  • Everything you need is included in the kit.
  • Fewer dropped calls
  • Faster Internet data speeds
  • Better voice quality
  • Texts that send quickly
  • Longer battery life

Your purchase is covered by our 30-day money back guarantee, so you can try it risk free, and our friendly, US-based technical support team is standing by to assist with anything you need. Your equipment is also covered by a 2-year manufacturer warranty, for extra peace of mind.

Recommended For

The CEL-FI DUO+ is recommended for any situation where you only need to boost Verizon 4G LTE and aren't able to mount an antenna outside. The units take just a couple of minutes to setup and start boosting Verizon LTE signal to your area that needs it most.

Please Note: The CEL-FI DUO+ for Verizon will only boost Verizon’s 4G LTE networks. All phones that support 4G LTE will get fast data speeds, but only phones that support VoLTE calling will be able to make and receive phone calls with the DUO+. All iPhone 6 (released in 2014) and later iPhones will support VoLTE calling. For Android, search Google for your phone model and “VoLTE” to see if it is supported.


The CEL-FI DUO+ is one of the more intelligent booster systems that we carry thanks to the companion CEL-FI WAVE app for iPhone and Android. The WAVE app allows you to many things, including:

  • Register the booster with your carrier, if necessary
  • See how well the system is working and troubleshoot it if necessary

How it Works

The CEL-FI DUO+ has a network unit that you place in the location in your home or office that gets the best Verizon 4G LTE signal, which is usually a window. You then need to place the coverage unit in the location where you need better cell signal, and then plug in both units.

The units will talk to each other wirelessly, analyze the existing signal, and then create an area of boosted cell signal radiating in all directions from the coverage unit.

Estimated Inside Coverage

The strength of your existing outside signal, measured in the location where you plan to mount the outside antenna, has a direct impact on the amount of inside coverage you'll get from a signal booster. The distance between the inside and outside antennas can also dramatically impact the size of the coverage area. The table below shows how much coverage you may get depending on your outside signal strength:

Existing Outside Signal Strength Estimated Inside Coverage
Strong (5 Bars) Up to 15,000 sq ft
Medium (3-4 Bars) Up to 10,000 sq ft
Weak (1-2 Bars) Up to 5,000 sq ft
None (0 Bars) No Coverage

Please Note: It is important to remember that there are many factors that impact the size of the inside coverage area, so actual results may vary from these estimates.

A Note About Bars on Your Phone

The bars on your phone take into account not just signal strength, but signal quality. The CEL-FI DUO+ can significantly increase the signal strength that your phone receives, but it’s very difficult to improve the signal quality. If you have a very poor quality outside signal, it’s possible that you’ll only get 1 or 2 bars inside with the booster, but the important thing is that you’ll be able to make calls and use data in places where you couldn’t before.

Will this Work for my Phone and Carrier?

The CEL-FI DUO+ is designed to boost only Verizon LTE.

Carrier Verizon
Supported Phones All Verizon Cell Phones, Hotspots, and any Devices that use Cellular Data
Networks 4G LTE Only (No support for 2G or 3G). Your phone must support VoLTE calling to make calls through this booster. Contact us for more information.
Frequencies 700, 1900, 1700/2100 MHz

Please Note: The DUO+ will not work with any carrier other than Verizon LTE. It will not work outside of the United States.

Kit Includes

The following components are included with the CEL-FI DUO+ kit:

CEL-FI DUO+ Signal Booster for Verizon 4G LTE Data and VoLTE Calls [Discontinued]


What You Should Know


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