Purpose built for IT administrators, security professionals, and small home environments requiring a stable solution for access control devices, asset tracking, or device authentication. CUID features: rewritable programming rated for 100,000 cycles and 13.56 MHz ISO14443A compliance, enabling cloning of IC cards with standard writers such as Proxmark3 or iCopy devices. Form factor and durability: 25 mm round adhesive sticker that combines an S50 chip with ASK encoding for stable data transmission, backed by industrial adhesive for permanent attachment on metal surfaces and equipment. Interoperability and standards: engineered with batch variable coil designs (typically circular) and default passwords 12F compatibility, the CUID electronic tokens ensure cross device functionality with readers while maintaining ISO14443 standards. Practical and installation details: compact, easy to apply sticker that delivers reliable performance in metal environments and works with common ISO14443 readers. Use scenario 1: data center and server room access control and equipment authentication by applying the sticker to metal doors, racks, or assets for authorized access and monitoring. Use scenario 2: asset tracking and inventory management in facilities by labeling value equipment, tools, or devices to enable precise tracking and verification. Use scenario 3: device authentication for lab equipment or industrial controllers to ensure only authorized devices interact with a system or network while preserving compatibility with ISO14443 readers.