HYYIKA 125kHz RFID fob Writable RFID Tags (T5577) 10-Pack
Quick take
This 10-pack of 125kHz T5577 RFID fobs is built for people who already have an RFID writer and want rewritable tags for access control-style systems. Buyers consistently report that programming works as expected and that the set is good value for RFID projects and replacing lost fobs. The biggest caveat is that the tags generally need to be programmed first, and compatibility depends on your reader format (some systems are explicitly not supported).
Pros and cons
Pros
- Rewritable 125kHz T5577 chips, designed to be programmed before use
- Includes keychain iron ring for easy carrying of each fob
- Buyers report smooth write and rewrite performance, with all fobs recognized in testing
- Made from ABS material with claimed high-temperature resistance (up to 190°F)
Cons
- Not plug-and-play for every system, some platforms are not compatible
- Requires writing an ID on the tag, so it’s not a solution for readers expecting pre-programmed cards
- Some buyers feel sensitivity is lower than certain original fobs (reader-dependent)
What buyers think
Buyer-review evidence is limited to a handful of reports, but the recurring themes are clear. Several reviewers describe successful programming and recognition when using an RFID writer, including scenarios like adding a replacement fob for residential gate access and using the tags for RFID cloning or testing. Build quality and day-to-day durability are mentioned positively, with the fobs described as lightweight but solid for everyday use. There is also a small amount of buyer feedback suggesting read sensitivity may vary versus other key fobs, which points to reader and environment differences rather than a guaranteed limitation for every setup.
What these 125kHz T5577 fobs are for
These are writable RFID fobs designed around a T5577 ID chip in the 125kHz family. That usually means they are a fit when you want to program tags for access control use cases like gate entry, building access, and similar 125kHz reader environments. They are also commonly used for experimentation, RFID project prototyping, and replacing individual tags you no longer have.
Compatibility and programming you should plan for
The most important part of buying any writable RFID tag is whether it matches your reader’s expected format.
Tags are not pre-programmed
These fobs do not come with a usable ID out of the box. You should expect to write an ID to the tag before you can read it with your access system or tester.
Supported 125kHz formats (and key caveat systems)
They’re marketed as writable for 125kHz ID format and H-ID WG 125kHz format, with the ability to be customized to a 26-bit Prox format. They are also described as compatible with T5567, T5577, and EM4305 style operation. Buyers and the product positioning also highlight use with HID-style systems and Flipper Zero for read and write workflows.
At the same time, the product notes explicitly call out incompatibility with certain systems (including Onity) and Proxmark3 RDV4, plus a compatibility limitation with Keysy duplicators. If you are currently using one of those specific tools or platforms, it’s a strong reason to pause and confirm tag-reader fit before buying.
Pros and cons
When they’re a strong buy
- You have, or plan to use, an RFID writer to program 125kHz T5577 tags
- You need a small quantity (10 fobs) for replacement, testing, or cloning workflows
- Your reader setup aligns with 125kHz T5577/HID-style expectations
- You want durable everyday carrying with the included keychain ring
When you should consider alternatives
- You need a pre-programmed card or you cannot access a write workflow
- Your system relies on a format or tool that is called out as incompatible (for example, Onity or Proxmark3 RDV4)
- You require consistent long-range sensitivity compared with a specific manufacturer’s original fob (sensitivity can vary by environment and reader)
Build quality, material, and everyday usability
The fobs are made from ABS high-temperature resistant material, with a claimed temperature tolerance up to 190°F. Reviewers also describe the fobs as lightweight but durable enough for day-to-day carrying. The included iron ring keychain makes them easier to attach to keys or a backpack clip, which matters because fobs are small and easy to misplace.
Value: a 10-pack for programming and replacement
With a 10-pack quantity, these fobs are positioned for practical use where you might need more than one tag, such as household replacements or small project testing. Reviewers specifically mention good value relative to the set size, and that the full quantity worked in their programming efforts. If you only need one card and you already know your exact compatibility requirements, you could potentially save money by buying a smaller quantity elsewhere, but that depends on your local options.
Verdict
HYYIKA’s 125kHz RFID fobs with T5577 writable chips are a solid choice if you want rewritable access cards for compatible 125kHz/HID-style environments and you’re comfortable programming tags before use. The main buying caveats are compatibility with your specific reader ecosystem and the fact that you must write an ID first. If those conditions match your setup, the buyer feedback points to reliable write-and-read behavior and practical everyday durability.
FAQs
Does this fob come pre-programmed?
No. It’s designed as a writable tag, so you should expect to program an ID before it will work with your reader.
What does “T5577” mean for compatibility?
T5577 refers to the tag chip family used by many 125kHz writer workflows. Compatibility still depends on your reader’s expected format (for example, 125kHz ID, H-ID WG, and Prox-related settings).
Will it work with HID systems or Flipper Zero?
It’s marketed as compatible with HID systems and described as working with Flipper Zero read/write workflows, but you should still confirm your exact reader format and settings.
Are these tags compatible with Onity or Proxmark3 RDV4?
No, the product notes say they cannot work with Onity systems and Proxmark3 RDV4.
How durable are the fobs for everyday use?
They’re made from ABS material with claimed high-temperature resistance, and buyers describe them as lightweight but durable for regular use.
Why might a writable fob not read consistently?
Most issues come down to mismatch between the tag format and the reader expectations, incomplete/incorrect programming, or sensitivity differences between original fobs and writable replacements.
Specifications
| Product Title | 125khz RFID fob Writable RFID Tags T5577 RFID Card 125khz fob(10 Pcs) for RFID Writer,Compatible with 1386 1326 H10301 Format Readers and Access Control Systems |
|---|---|
| Category | Electronics > Security & Surveillance > Home Security Systems |
| Brand | HYYIKA |
| Manufacturer | HYYIKA |
| Model Number | T5577 |
| Color | T5577 Key Fob |
| Material | Polyethylene Terephthalate |
| Size | 10pcs |
| Brand Name | HYYIKA |
| UPC | 768795806329 |
| Unit Count | 10.0 Count |
| Number of Items | 10 |
| Manufacturer Part Number | T5577-Key-10 |
| Finish Type | Polished |
| Item Shape | Rectangular |
| Ink Color | Black |
| Number of Labels | 10 |
| Material Type | Polyethylene Terephthalate |
Available variants
Color
- T5577 Key Fob
- T5577 Card
Size
- 10pcs
- 30pcs
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