Coil Master 521 Tab – A New Device, Not a Toolkit

I wanted to do this review for the Coil Master 521 Tab mostly because I use Coil Master toolkits all the time, at home in New Hampshire, in Florida, on the road, just about anywhere. Being able to whip out a toolkit and some wire and build a coil, or coils, for my “of the moment” RDA, or RTA, truly feels like freedom to vape exactly how I want, no matter where I am.

Once I had used the Coil Master 521 Tab I realized it was definitely a cool device to have, and since the price tag was fine by me, I had to get one. But how do you review what is essentially an ohms reader on steroids? Luckily, after a few days I realized it could be a lot more than a glorified ohms meter.

If you build coils you know the name Coil Master. For the past couple of years this company has seen success after success based on a very simple idea; gather up all the tools and supplies people need for coil building, make a nice cloth or leatherette slipcase for it, and put it on the market at a price most people can afford.

Coil Master 521 Tab – A Spinfuel eMagazine ReviewEvery time Coil Master needs to juice their product line they take this same idea, the “toolkit for coil builders” and add a tool, change a tool, improve the slipcase, include more tools or supplies, and so on, and get it to market. Builders buy them, hell I buy them even though I’m building less and less, because each time Coil Master makes them a little bit better.

With the introduction of the Coil Master 521 Tab, Coil Master is finally offering something truly different. If you’re happy with the toolkit idea you may or may not see the value of this new ‘device’ (it is a device more than it is a toolset), but if you used one you’d understand immediately why serious builders love the thing.

Coil Master 521 Tab – A Device

The Coil Master 521 Tab runs on a single 18650-battery. This power runs the super-accurate ohms’ meter, pushes current to certain mods to check for voltage drop between the attached mod and the attached RDA/RBA, and it can even fire the coils on the build deck, essentially becoming one strange looking mech mod. The only items you get that could be perceived as tools though, are the alligator clips. Other than that, the 521 Tab is a device, not another toolkit.

The Coil Master 521 Tab runs about $40 (DirectVapor), and if you own a Coil Master toolkit, or some other toolkit for coil building, I highly recommend taking the next step and picking up the 521 Tab because it will make the job of building coils easier, and perhaps even more fun.

Coil builders that love to build the truly remarkable builds will especially appreciate the build deck, up high enough, sitting in the middle of turntable shape, that reaching, turning, and twisting to reach the harder places is easily accomplished.

During the past week I’ve used the Coil Master 521 Tab a lot, and I’ve compared the ohms’ meter to the cheaperCoil Master 521 Tab – A Spinfuel eMagazine Review ohms’ meters that come with the toolkits. I’m not going to tell you the accuracy was dramatically different, it wasn’t, but I can’t help thinking that I trust the meter in the 521 Tab more. Even though most of the coils registered identical ohms’ levels on the cheaper ones and the 521 Tab, the Tab exudes more professionalism. I know, sounds stupid, but if you have one you know what I mean… I hope.

I do love the option of building on this deck, being able to flip a switch on the side of the box and getting an accurate resistance reading, then flipping it again to fire up the coil. If for any reason I don’t like what I see, I can tweak the build as much as I want and test again. Finally, when I do get the coil exactly where I want it I can thread the organic cotton, saturate with ejuice, and see my new build in action while its still on the 521 Tab. Hell, if I wanted to I could assemble the RDA or RTA, lift the 521 Tab and vape from it. A little weird maybe, but I would get a 4.2v mech mod vape from it. Try doing that with a pocket sized ohms’ meter.

Coil Master 521 Tab – A Spinfuel eMagazine ReviewFor the truly advanced, the Coil Master 521 Tab can test the amount of voltage drop a certain coil/RDA/RTA set up with a certain mod will have. All that’s needed to be done is to put on the included adapter arm, attach the mod to the 510-threading and place the RDA/RTA in the ohms’ meter slot in the middle of the turntable area and fire it up. You can see the actual drop off in real time. Most vapers have no need to do this, only the most advanced would even care. Still, there are plenty of high end vapers out there that would love to own a tool like this.


The Coil Master 521 Tab is a nifty device to have if you build your own coils, and especially if you want to take that coil building to new heights. The 521 Tab isn’t a must-have device for builders, but if you have the forty bucks and you want to make your life a little more fun while building, the Coil Master 521 Tab is a nice treat.

What You Get:

  • 1 x Coil Master 521 Tab
  • 1 x Voltage Checker
  • 2 x Terminal Connectors
  • 1 x Micro-USB Charging Cable
  • 1 x User Manual

 Features and Specs:

  • Ohm Meter
  • Voltage Checker
  • Rebuilding Deck
  • Test Fire Atomizers
  • OLED Screen
  • Reverse Battery Protection
  • Powered by (1) 18650 Battery (Sold Separately)
  • Resistance Measurement Range: 0.01 – 9.99 ohm
  • Voltage Measurement Range: 0.3 – 9.99V
  • Minimum Resistance Rate: 0.2 ohm
  • Spring-Loaded 510 Connection
  • Micro-USB Charging Port

Get one from DirectVapor for just $49.95 –

Tom McBride