SX Mini M Class Review: High-Class Vaping!

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Expensive, but worth it!

I have been a fan of the SX series since I bought the Sigelei 20-watt over a year ago. Yihi doesn’t disappoint with the SX350J chip that comes in the feature-packed SX Mini M Class. If the name makes you think of a Mercedes, it should and not just because of the name.

SX Mini M Class Review: High-Class Vaping!

The M Class feels like a Mercedes in quality and features; it is high-class vaping! At $199.99, it’s definitely one of the more expensive mass-produced mods on the market right now, but it’s nearly perfect.

SX Mini M Class Review: High-Class Vaping!

SX Mini “M Class” 60-watt mod with Temperature Control


  • Chipset YiHi SX350J
  • Updated Materials: New Zinc Alloy body with slightly more rounded corners
  • Stainless Steel Spring Loaded 510 Connector
  • Reverse Polarity, Short, Low Voltage and Overheat Protection
  • Software Upgradeable via USB Port

Temperature Control Specs:

  • Joules Min Output: 5 Joules  Max Output: 50 Joules
  • Joules Mode Min Resistance 0.12 ohms  Max Resistance: 1 ohm
  • Temp Limits Min: 200F / 100C   Max: 580F / 300C

Wattage Specs for Single 18650 Battery Mode:

  • Output Min Watts:5  Max Watts: 60
  • Output Min Volts: 1  Max Volts: 9.5
  • Output Max Current: 40 amps
  • Min Resistance 0.08 ohms  Max Resistance: 3 ohms
  • Efficiency 93%
  • USB Charge/Update

In The Box


The SX Mini M Class comes in a fancy gift bag with a sturdy box lined with foam to protect the device.

Here’s what came in the box.

  • Yihi SX Mini M Class
  • USB-to-Micro USB Charging Cable
  • User Manual
  • Warranty Card
  • Gift Box and Bag

That’s all. No extra fluff. All the fun is inside the device.


The SX Mini M Class is crafted from high-end materials. Zinc alloy casing, 304 stainless steel battery tube, and stainless steel buttons. It’s ergonomic and while I never owned an SX Mini S Class, Hcigar listened to feedback and made changes to make the M Class even better. This device is much heavier than it looks, compliments of the high-end materials I mentioned. The popular c-frame styling that some high-end, custom box mods are using allows the M Class to feel perfect in hand.

The SX Mini M class has 3 color choices, silver/gray, silver/black, and silver/rose (the color I chose).


SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping!

The front of the SX Mini M Class is where all the fun begins. The Micro USB charge port is at the very bottom of the front, which makes charging the device convenient. You won’t have to lay the device on it’s side to charge, keeping your tank or RDA upright. The Micro USB port can also be used to update the SX350J’s firmware. Just above the Micro USB port is the up and down buttons used to make adjustments. A very bright, informative OLED display sits in the center of the front panel. As the device moves to the top, the front panel curves towards the back and the power/fire button follows the same contour.  The back of the C frame of SX Mini M Class is free of anything but contours that make the device feel perfectly formed for my hand. The right and left sides of the device have just some styling curves that are absent from the regular SX Mini.

SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping!

The bottom of the M Class houses the cover for the stainless steel battery compartment. This bottom cap is a little tricky to get going but once you’ve got it lined up and ready to screw back on, the threads are buttery smooth. I would warn new users of this mod to be careful about getting it started. The cover has a notch in it so you can use a coin to screw it in place quickly. The battery goes in positive side up and Yihi recommends an 18650 battery that is rated for at least 30 amps.

The top of the SX Mini M Class houses a large, fat daddy-like 510 connector. The SX Mini S Class had similar connectors but the air channels extended all the way to the edge of the connector. Most tanks and RDAs these days do not pull air through the 510 connector base, so this is a non-issue in my opinion. The M Class has a brass spring-loaded 510 connector and I didn’t have any problems getting any of my tanks to sit flush on top. The photo below shows a couple popular atomizers I used to test the SX Mini M Class out.

SX Mini M Class Review: High-Class Vaping!

Size Comparisons

SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping!

Here is the SX Mini M Class posing with the Pioneer4you iPV 4 temp control mod.

SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping! SX Mini M Class Review: High-Class Vaping!

The SX Mini M-Class vs a few items that you might be familiar with, the iPhone 5c (left), a standard 18650 battery (center), and a 30 ml bottle of e-liquid (right).


Most of my usage was with sub-ohm tanks at 0.5 ohms and 1.2 ohms. I also used an RDA with a .2 ohm kanthal build. If you are looking for a review with real-world experience with RDA builds with nickel wire, look around some more. I didn’t do any temp control testing with anything but the Kanger SubTank nickel coils, which performed quite nicely with the M Class. I didn’t experience any dry hits and the vapor was nice and cool.

The SX Mini M Class toggles between wattage mode (kanthal) and joules mode (nickel) so easy that you can switch back and forth as often as you’d like with no hassles.

One of the best features is the anti-dry burn feature. The SX350J chip that the mod uses senses the condition of the cotton and will display a message ( “Dry Coil. No liquid.”) when it detects the juice is all gone.

Safety Features

The SX Mini M Class comes with all sorts of safety features! In addition to being able to lock the device to prevent accidental firing, it also has reverse polarity protection, short-circuit protection, low resistance protection, low battery voltage protection, and overheating protection.

Temperature Control

As I mentioned above, I didn’t do much testing with temp control builds. I could have saved $20-30 and bought the S class instead but I wanted a device that could do temp control if I wanted to. I will just say that I tried temp control and it worked well. I am more of a tootle puffer and I don’t vape in a way where I need temp control. I didn’t experience a dry hit or taste any cotton burn whatsoever. Setting up for temp control was quite easy as well.

I am going to refrain from explaining temp control with the SX Mini but here is a video from the manufacturer that shows how it works.

SXMini M Class Temperature Control Video

Battery Life

This device uses a single, user-replaceable 18650 battery. In my testing, I used a couple of different Efest 2500mah, 35amp batteries. The initial charge was obtained using an Efest LUC V4 battery charger. After that, I used the Micro USB charge port to fully recharge. I am a fairly heavy vaper that goes through approximately 15 ml of e-liquid a day. Using a 1.2-ohm coil at 15 watts, I was able to get an average of 9 hours on one battery. This isn’t 9 continuous hours obviously, but this is during the day with pretty heavy vaping. With a .5 ohm coil running at 35 watts, I got 3-4 hours on average. The overall battery performance seemed a bit less efficient than other single battery mods I have owned. If you are using .5 ohm or lower tanks or drippers, be prepared to carry spare batteries.


The Yihi SX Mini M Class is a home run, better yet, a grand slam of a device. The price is quite daunting to some, but once you realize the quality materials, construction, and features that the M Class has, you understand the price. It’s slightly more expensive than the Vaporshark RDNA and more than twice the price of the Pioneer4you iPV 4 which seems to be one of the more popular mods for temp control right now, the popularity that comes from its affordable price and 150 watt power max. You get what you pay for and what you will pay $199.99 for is a solid zinc alloy c-frame device with one of the most advanced chips on the market and wonderful ergonomics. If you have a chance to handle one and then handle one of the other temp control devices out right now, you’ll know that the price of the SX Mini M Class isn’t too steep for what you get.

The M Class isn’t for everyone.

If you are after a high-quality, well-built device with temp control and you don’t mind using a single battery device, this is for you.

If you just want a good vape, but don’t want to pay a premium price for a premium device, the SX Mini M class is probably not for you.

I prefer a device with dual 18650 batteries myself but I really enjoyed using the SX Mini M Class. There are other quality temp control devices on the market now, but this still seems to be desired by those that can and can’t afford one. For those that can afford one, I highly recommend the SX Mini M Class. It is well worth the price for the quality you get.


Source: I purchased the SX Mini M-Class from Bama Vapor in Birmingham, Alabama. You can purchase online at many retailers that sell high-end mods.

What I Like: The look and feel; The SX 350J chip; The temperature control experience, and the beautiful screen.

What Needs Improvement: Battery life-This can’t really be improved on since it’s a single battery device and you can’t really pull off two batteries in a mod this size without adding the goofy looking extension tube; The Gravity Sensor – The gravity sensor can frustrate until you learn to control it. I think there should be an option to disable the sensor altogether.


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