20pcs NTAG215 NFC Tag Black NFC Stickers Round 25mm(1 inch)，Blank NTAG 215 Tags，Work Perfectly with TagMo and All NFC-Enabled Cell Phones&Devices

I used these on various electronics- computer devices, the transformer boxes on plugs and the like. They are suitably durable and stick really well and are unobtrusive. I haven't had a problem yet with them and I'm really liking what I can do with them.These DO work on metal. Reception by any given person's phone depends on the phone in part- not all phones are made equal and neither are the NFC chips that are put in phones to detect signal, and even how the phone is held can matter. If I held my phone one way it would have a hard time detecting metal or no metal, and if I held it another way it picked both right up. I put a reg tag and this one on two types of metal dog bowls. One aluminum and one stainless steel. My phone failed to read the regular tag on both, it was able to read this tag on both but repeating it over and over, once or twice I had to be a little careful how I held my phone or had to go over it a second time to get the reading. But I got it and it was there.

I'm using these to activate shortcuts on an iPhone. I haven't needed to program them -- they work out of the box with the built in NFC reader. You do have to point the top of the phone at them - they're not detected just anywhere - but once you work that out they seem to work very well.

I purchased 100 of these NFC tags - two 30-packs and two 20-packs - and am happy to report 100% success writing to them with my iPhone 11 Pro Max and the freely available NFC Tools app.To clarify, this is my first experience with NFCs and, admittedly, I was a bit cautious, given the failure rates reported by some reviewers. So, I over-ordered, expecting to throw some "duds" away, but this never happened. Yes, I received a couple of write errors on the first few tries, but this ended up being attributable to the concrete and granite counter tops I was working on. Holding the NFC tags in my hand, rather than laying them on my work surface, fixed the issue. Furthermore, I quickly homed in on the iPhone's sweet spot - at the very top edge - and was off to the races. I wrote all 100 tags in about three minutes. For quality control, I checked (read) about 30 of 'em and they passed with flying colors. Not one failure.What's the effective read/write range? My iPhone has an Apple Silicone Case on it and the read/write range is consistently 1". Removing the case reduced the effective range to about 1/2". [I know. Huh?!] My iPhone also has a 2" Volport MagicPlate for magnetically attaching the phone to windshields, tripods, selfie sticks, etc. But it's located in the center of the phone and, to my knowledge, shouldn't affect NFC read/write range. If I could remove the plate without destroying it, I'd test it, but alas, this isn't an option.I will certainly be reordering these, since my favorite business card printing service doesn't yet offer NFC options. Until they do, I'm sticking these to the back side of my business cards, right next to the QR code. I'm a music composer and producer by trade and it's pretty cool that folks can tap the cards and stream my music on the spot. Of course, for this, reliability is critical, so I appreciate how well these tags are working so far. Great product!

But with the tent of labeling every medication I take so I can log it with my phone. It works great. It takes well to the bottle cap, allowing the phone just just stay close by it is a great value for the price.

Hard to use