10pack 125 kHz rewritable RFID keyfobs, Black Overview These blank 125 kHz ID RFID keyfobs provide a compact, durable solution for creating and managing proximity tags. Each fob is rewritable and compatible with common 125 kHz tag formats, making them suitable for access control programming, replacements, and custom ID projects. Key features and benefits Pack of 10 black keyfobs for bulk replacement, testing, or distribution. Rewritable T5577 chip (model T5577 compatible) that supports 125 kHz ID format and HID WG 125 kHz format; can be customized to 26bit Prox format. Compatibility with T5567, T5577, and EM4305 style tags for easy cloning and format conversion. Frequency: 125 kHz, with sensing distance typically 2.5 to 10 cm (1 to 4 inch). Data storage life up to 10 years for reliable longterm use. Compact size: 40*30*4 mm (1.57*1.18*0.16 inch) fits easily on key rings or badge holders. Durable construction: quality copper coil inside and ABS plastic casing that is waterproof and heatresistant for everyday use. Note on use: tags are blank without preprogrammed card numbers. They must be written with a 125 kHz RFID card writer before they can be used with RFID locks or read by card readers. Practical applications Access control replacement: program tag numbers to lost or damaged proximity fobs for office or facility doors. Event or temporary access: quickly write eventspecific IDs for staff, contractors, or visitors and reuse the fobs afterward. System testing and development: use rewritable tags to test readers, copy card data for migration, or develop custom access workflows. What this product solves Eliminates the wait and cost of ordering preprogrammed tags by allowing onsite programming and reuse. Provides broad compatibility to simplify migration between different 125 kHz systems and reader formats. Offers a durable, compact tag option suitable for daily carry and longterm storage of ID data. Important usage note These keyfobs are blank on delivery. A compatible 125 kHz RFID card writer is required to write card numbers before the tags can be used with RFID locks or read by a card reader.