The 540-"needle" roller and needle cartridges with more than 12 needles have fake needles (they are cheap stamped knives!) that cause permanent scarring.

Scars on the cheek from a 540-"needle" dermaroller.
Photo from our customer, who desperately asked whether we could help him.

This person also has scarring from the same type of stamped knives and also asked us whether we could help her. With permission.

All the most heavily promoted/sold dermaneedling instruments in the world, be it pen-type electric needling devices or the traditional dermarollers or dermastamps are made by one single, absolutely gigantic Chinese company. That company has not the slightest clue about dermaneedling and only cares about making as much money as possible. They say: "Look! We have such a sophisticated roller, it has many more needles than the competition!" The problem is that so many needles are technically impossible to put on a small roller and even if they were to make such a (larger) roller, it would cost an utter fortune.
So they stamp what can more aptly be called "knives" out of surgical steel or Titanium.

TINY KNIVES, SLICING ALSO HORIZONTALLY THROUGH SKIN..

Closeup of Dr. Pen's 42-"needle" cartridge. Click photo for full size.

Above a photo we made of the most recent version of the official (no knockoff) Dr. Pen's 42-needle cartridge. Their 36-needle cartridge looks the same. Click the photo to see it in full size. It does not use what we understand to be needles at all! Quite frankly, selling this to unsuspecting customers shows the complete disregard, bordering on contempt these Chinese factories and resellers have for their end users in their arrogance of knowing it's virtually impossible for westerners to successfully sue them. Unless you're Elon Musk, good luck trying to get a Chinese megacorp held liable for damage to your skin.

This (link) is the company that makes Dr. Pen:
"Guangzhou EKAI Electronic Technology Co.,Ltd is a professional manufacturer of beauty devices in China". They hold the Dr. Pen trademark with USPTO.

They've been in business since 2008, two years less than ourselves. They're so "professional", that in all those years in business, they never even bothered to quality-check the front page of their corporate website:

(See red "1") Dr. Pen's fake "needles" do not have a sharp conical tip as we expect needles to have. Instead, Dr. Pen's "needle" tips are ragged, roughly semi-circle-shaped "slicers". It's should be clear that we don't want any of those slicing edges to move horizontally though our skin, which always happens to a certain extent due to the horizontal movement of your hand while the needles are inside the skin or in the process of piercing it.

(See red "2") The tip-end of Dr. Pen's "needles" are also shaped like slicing knives, being much tinner than the round diameter of real needles, as well as having sharp edges. Dr. Pen simply can't avoid that, with so many needles in a cartridge. Their 36-needle cartridges also have fake needles. These final "needle" ends can therefore also act like knives, traveling horizontally through the skin. When we use the needle orientation in the photo as an example, this happens when the direction of movement is SE or NW. And the faster you move the pen, the worse the slicing effect will be.

(See red "3") Normal needles aren't flat or quadratic but round. A round needle, when pushed a little horizontally through the skin, either when inside the skin or in the process of penetrating it, has the most possible achievable difficulty, slicing it. Whereas in this case a quadratic shape presents a 90 degree angle, in this case the angle itself is not dramatically sharp but due to the perfection in its manufacture, it has no bluntness at all on its leading edge - which is not that many molecules wide in this case - we have no electron microscope to prove this but we offer a $1000 award if you can arrange that for us), meaning that it, in certain horizontal movement directions, also will be able to slice through the skin. In our photo's case that would be the directions NE, SE, SW and NW.

As a result of the above issues 1, 2 and 3 with Dr. Pen's and other manufacturers' needle cartridges, any resulting scarring depends on random factors such as the orientation of the "needles" in the cartridge, semi-random factors such as how fast you move the cartridge over the skin and factors that depend on how often you treat and how prone that skin area is to scarring, which again depends on more-or-less random factors such as age, genetics etc. Initially, scarring will be very thin and not prominent.

The solution? Buy only instuments with real needles. Those instruments never have more than approx. 192 needles in case of dermarollers, 35 needles in case of dermastamps (except when they're very large such as our 80-needle stamp) and 12 needles in case of dermaneedling cartridges for electromechanical needling "pens". The needling instruments (incl. the needle cartridges for our Derminator) we sell aren't made in China but in South Korea. The Derminator itself is made here in Europe by our own employees. Below a photo of our Owndoc Derminator 12-needle cartridge:

Closeup of Owndoc's 12-needle cartridge. Click photo for full size.

We use real needles! Our cartridges are made in South Korea and that company imports Japanese needles because the manufacturing of such fine, yet extremely rigid needles is a rare craft where trade secrets for machinery and alloys and much experience are involved.

Us using actual needles (that also are much thinner than competitors' real needles, when they use them, ours have a diameter of 0.15 mm or 34.5 AWG wheras all others have 0.25 mm or 30 AWG, which seems minor but the difference is a nearly three times smaller cross-sectional area!) is why people say that our Derminator® hurts less than Dr. Pen's flagship device, the "Ultima A6S Professional Plus":

Note that the person who agreed in the above screenshots is "Claudia Glows", who went out of her way to try to prevent people from buying our device because she's an affiliate for - guess what - Dr. Pen! The companies that make dermaneedling instruments aren't actual, serious, real medical device manufacturers. They are bandwagon-jumpers of whatever is trendy in the Beauty niche. They're in the electronic beauty device business. They make whatever sells well and they have in-house experts that find the cheapest way to manufacture. No staff that knows or cares about side effects. All those Chinese pen-type buzzers are based on permanent makeup pen technology from decades ago. They're still coasting on that ancient, too-feeble tech and the high duty-cycle of their sluggish sewing-machine-like vertical motion is such that even real needles cause microtearing: