It wasn’t that long ago that a box mod capable of 175-watt output would be the size of a paperback romance novel (and about as reliable). Today, vape manufacturers are finding new ways to squeeze unbelievable amounts of power out of extremely compact devices. Take, for example, the new Sigelei Fuchai Duo-3 box mod, which offers a lot of gusto for the size, and the price.


Measuring just 85mm tall, and a comparatively narrow diameter, the Fuchai Duo-3 is a slender but potent zinc alloy device, capable of 175 watts of power in its stock configuration, and up to 75 more watts with the optional third-battery extension door (sold separately).


The Duo-3 is a complete reinvention of the standard Fuchai design aesthetic, as the 1-inch, full color OLED screen, minimalist design and oversized fire button are all new elements for the series. Though the Fuchai GLO hinted at some of this look and feel, the Duo-3 comes across as a new brand, and a new direction for Sigelei – and we think it’s a good move.


Under the hood, the proprietary chipset gives Duo-3 owners a full temp control suite, TCR customization, and the intriguing “Temperature Factor of Resistivity” mode, which we’re looking forward to testing extensively, to see if it’s a way to improve the experience, or just more marketing talk from ambitious ad teams.

More About the Sigelei Fuchai Duo-3

Though we haven’t really tested the Fuchai Duo-3 past an initial run-through, so far we really love the way it feels in our hands. I’m not a huge proponent of front-facing fire buttons, but the compact style of this mod makes the oversized fire key a pleasure to operate. Plus, the Duo-3 ramps up exceptionally fast, even on higher wattages. This bodes extremely well for our full test regimen.


What also bodes well is how the Duo-3 features ample venting on the bottom of the device – something I feel is VERY important on a mod cramming this much power into such a compact space.


The color screen is sharp and legible, if not a little gaudy with its multiple hues. Maybe it’s just preference, but the simple silver and black test model seemed to call for an equally streamlined display. I’ll let you know if that opinion changes when the full review appears in the next week or so.


More importantly, our initial impression of the Fuchai Duo-3 is that it just seems “to work.” We can’t say anything definitively YET, but so far, there has been no problems making adjustments, reading complicated coils or upgrading firmware.


The series has endured a slightly rocky history, but with the Fuchai Duo-3 (and the pretty awesome GLO), it appears Fuchai is no longer just a secondary brand for Sigelei. Keep an eye out for our full review within the next week or so.

Sigelei Fuchai Duo-3 Specs

Sigelei Fuchai Duo-3 175W TC Box Mod specs:

  • Dual 18650 High-Amp Battery – Not Included
  • Wattage Ouput Range: 10-175W
  • Voltage Output Range: 1-7.5V
  • Min Atomizer Resistance: 0.1ohm
  • 1-Inch OLED Display – Full Color Resolution
  • Ni200, Titanium, and Stainless Steel Compatibility
  • Temperature Coefficient of Resistance (TCR) Adjustments
  • Temperature Factor of Resistivity (TFR) Adjustments
  • User-Friendly Preset Modes
  • High-Grade Zinc Alloy Construction
  • Three-Button Operation
  • Large Oversized Firing button
  • Removable Battery Cover – Lock Switch
  • Reverse Battery Protection
  • Low Resistance Protection
  • Battery Imbalance Protection
  • Low Input Voltage Warning
  • Short Circuit Protection
  • Overheat Protection
  • MicroUSB Port – Firmware Upgrades
  • Spring-Loaded 510 Connection


Sigelei Fuchai Duo-3 175W TC Box Mod Package contents:

  • 1x Sigelei Fuchai Duo-3 Mod
  • 1x USB Cable
  • 1x Battery Cover
  • 1x English User Manual