The following transponders are available:

• Check card, 2,13" x 3,35" x 0,04" (54 mm x 85mm x 1 mm)*
  
• Combi card (check card with magnetic stripe).*
  
• Key holder
  
• Cards are blank (white). Customized print available

The transponder contains an antenna and the electronic on an integrated circuit. The energy received is used to build up the necessary power to supply the electronic and this electronic creates a response signal to the reader. The better the match of the received signal at the built in antenna in the transponder, the better the distance achieved. Check card transponders have the longest range.