A tarsal-jess transmitter attaches to the bird's leg using a leather jess (strap) passed through a small stainless steel loop on the transmitter. This attachment method is primarily used on raptors. Advantages of this design include no encumbrance of the neck, wings, or body. This is especially important for birds of prey who need to maneuver during in-flight chases. Field range with a tarsal-jess transmitter is good. Transmitter life is less than some other designs. Metal tab for attachment with Jess supplied by user.

Series	Weight (grams)	Life (days)	Description
A5000	8.5	112-312	Coin shape.
A5300	16.0	312-560	Flattened rectangular shape, tab mounted in middle.