ANTI-METAL 28mm Round Disc Tag in White HARD PVC plastic with strong 3M glue PLAIN WHITE. These are about 1 mm thick and the NFC technology is completely encased in PVC so waterproof and weather proof. They can safely be used on metal surfaces due to the ferrite protection on the back.
These are manufactured for business and used for commercial use so very strong and durable as well as having a strong 3M adhesive applied. They also have an excellent reading distance. They are weather proof, waterproof, dust proof and can be outside as well as inside.