The short answer is, any tag that will work with your chosen device.
However, tags with 13.56Mhz and ISO 14443 or 15963 should work.
If you are at all unsure about which tags to get, you may order tags from Trackforce; or tell your tag provider which device(s) you plan to use, they should be able to determine which tags are compatible (some will even provide free samples to test).
There are also many form factors (shapes) and options. Trackforce can provide you with "button tags" and "Card tags". Any other types should be ordered from your tag provider.
- Button Tags: A small disk. Most often used as tour checkpoints.
- Card Tags: The shape of a business card. Most often used as badges/User IDs.