Yellow 12PCS T5577 125KHz Writable Rewritable RFID Key Tags Keyfobs Product overview These yellow key tags use the T5577 125KHz writable and rewritable chip to provide flexible identity and access management. Each tag can be programmed and rewritten up to 100,000 times, enabling reuse and rapid reconfiguration for changing access needs. Key benefits Reprogrammable and cost effective: write and rewrite each tag up to 100,000 times to avoid replacing cards when access permissions change. Broad compatibility: can duplicate many common 125KHz card types, including EM4100, TK4100, and HT4168, making them suitable for mixed systems. Reliable construction: built around a T5577 ID chip and a pure copper induction coil for stable performance. Easy to use and attach: keyfob form factor designed for convenient carrying on key rings or lanyards. Features Frequency: 125KHz Chip model: T5577, writable and rewritable Write cycles: up to 100,000 times Compatibility: supports duplication of EM4100, TK4100, HT4168 and other 125KHz formats Materials: durable ABS cover and pure copper induction coil Color and quantity: yellow, 12 pieces per pack Practical use scenarios Office access control: provision tags to employees for entry to doors, meeting rooms, and secure zones. Reprogram tags as roles change without issuing cards. Attendance and time tracking: use the keyfobs for employee check in and check out systems that accept 125KHz credentials. Multi‑site or mixed systems: duplicate existing 125KHz cards to these T5577 keyfobs to standardize credentials across readers and reduce replacement costs. What you get A set of 12 yellow T5577 125KHz writable key tags ready for programming and attachment to key rings or lanyards. Suitable for access control, attendance systems, elevator or parking access and other applications that accept 125KHz credentials.