1 c-ring (18mm. high) with a three alpha code (on right tarsus) and 1 c-ring (9mm. high) with two alpha code.
1 c-ring (18mm. high) with a three alpha code (on left tarsus).
1 c-ring (blue) with a white three alpha code (on right tarsus) and metal ring (on left tarsus).
note 1 : two c-rings used in case of adult breeding birds.
note 2 : one c-ring used in case of young/on the nest ringed birds.
note 3 : birds with a blue ring are ringed at the airport Maastricht-Aachen (The Netherlands).
