) Allflex FDX EID Tags are tamperproof, single use tags that utilize Full Duplex Technology. Each tag is printed with the unique 15-digit ID number that is stored within the tag's FDX transponder. Tags can be visually verified with printed tag ID number or automatically verified with use of a reading device. Allflex FDX EID Tags are made from rigid plastic tag with a tamperproof cap. Includes Global extended male buttons. Apply with Universal Allflex Tagger (remove the clip) or Allflex Retractomatic. 1.20” dia x 0.17 thick.