Let's talk about these E-TECH RFID cards that I've been using for my small office access control system. First off, the price point for 200 cards is absolutely unbeatable - it's what initially drew me to this product.

The cards feel surprisingly durable despite being only 0.8mm thick. I've dropped them, scratched them against door frames, and even accidentally ran one through the washing machine (oops!), and they still work perfectly fine. The waterproof claim definitely holds true.

Compatibility has been excellent in my experience. They worked seamlessly with our existing 125Khz RFID readers and time attendance system without any programming needed. Each card's unique ID makes employee tracking simple.

However, there's one major caveat: these are read-only cards. As some reviewers noted, you CANNOT clone or copy these cards to make duplicates. This wasn't an issue for our use case (we just assign new cards when needed), but could be problematic if you need backup copies.

The white printable surface works well for labeling with permanent marker, though I haven't tried actual printing on them yet. They're perfect for basic access control but don't expect advanced features.

Bottom line: For straightforward access control needs where you don't require card cloning, these offer incredible value. Just be aware of their limitations before purchasing.